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Balbharti Maharashtra State Board Class 6 History Solutions Chapter 10 Ancient India: Cultural Notes, Textbook Exercise Important Questions and Answers.

Maharashtra Board Class 6 History Solutions Chapter 10 Ancient India: Cultural

Class 6 History Chapter 10 Ancient India: Cultural Textbook Questions and Answers

1. Answer in one sentence:

Question 1.
Make a list of ancient Indian universities.
Answer:
The ancient Indian universities are Takshashila, Vamasi, Valabhi, Nalanda, Vikramshila and Kanchi.

Question 2.
Make a list of the Indian goods that were in demand in foreign countries.
Answer:
Indian goods like fine textiles, ivory, precious stones, spices, beautifully made earthen ; pottery were in great demand in foreign countries.

2. Name the following:

Question 1.
Epics and poetic composition of ancient India.
Answer:
Epics Silappadhikaram and Manimekhalai and Arsha epics Ramayana and Mahabharata and Paumchariya a poetic work are composition of ancient India.

3. Fill in the blanks:

Question 1.
The epic Ramayana was composed by rishi
(a) Vyas
(b) Valmiki
(c) Munni
Answer:
(b) Valmiki

Question 2.
The science of Indian medicine is called
(a) Ayurveda
(b) Homeopathy
(c) Alopathy
Answer:
(a) Ayurveda

Question 3.
Thousands of students could live at the University.
(a) Kanchi
(b) Takshashila
(c) Nalanda
Answer:
(c) Nalanda

4. Answer in brief:

Question 1.
Explain what is meant by ‘Tipitaka’.
Answer:
Tipitaka is a Buddhist religious text written in Pali. It contains three categories of texts.

• Sutta Pitaka
• Vinay Pitaka
• Abhidhamma Pitaka

Question 2.
What is the message of the Bhagwad Gita?
Answer:

• The Bhagwad Gita tells us that each one of us should do our duty without expecting rewards.
• It also says that the path of devotion to God is open to all.

Question 3.
What aspects does Ayurveda take into account?
Answer:
Ayurveda is a very old traditional Indian medical science. Ayurveda not only seeks to understand the symptoms, diagnosis and treatment of an illness but also takes into account the prevention of the illness.

Question 4.
What is meant by Sangham Literature?
Answer:
Sangham means a gathering of learned men. The literature that is compiled in such gathering is known as Sangham literature.

5. Discuss:

Question 1.
Art and architecture of the Mauryan and Gupta period.
Answer:

• Indian architecture reached its peak during the Mauryan and the Gupta periods.
• The stone pillar erected by Emperor Ashoka at various places are excellent examples of Indian sculpture.
• The stupa at Sanchi and cave sculptures at Karla, Nashik, Ajanta, Ellora, etc. show that the same tradition advanced even further.

6. What would you do ?

Question 1.
How would you obtain information about Ayurvedic medicine and use it in your day to day life?
Answer:
I will try to get information about Ayurveda from different literature that is available either in bookstores or on internet. I will try to deal with minor ailments like cough, cold, acidity, aches and pains in day to day life through ayurvedic stores. I will try to improve my health in order to prevent ailments by taking ayurvedic medicines to improve my immunity.

Question 2.
On a trip to a historical site, your friend in writes his name on the structure.
Answer:
When on a trip to a historical site, I see my friend write his name on the structure, I will gently tell him the importance of historical monuments and also how the ancient Indians must have built it with lots of effort, without modern technology and equipment. Thus invoking respect for the ancient fellow Indians is my friend. Also telling him how proud we Indians should be of their art and talents.

7. Observe the picture of the stupa at Sanchi and obtain more information about it.

Answer:
Sanchi is an outstanding specimen of Buddhist art and architecture. The Sanchi stupa is one of the best preserved early stupa in central India. The Sanchi stupa is surrounded by a railing with four carved gateways facing in all four directions. An interesting characteristic about Sanchi stupa is that Lord Buddha has been symbolically represented by footsteps, wheels, thrones, etc. rather than by his own image. The Sanchi stupa is one of the most wonderful structures of ancient India.

Activity:

• Obtain information from the elders in your family, about some special buildings in your neighbourhood.
• Visit some historical buildings, memorials in your neighbourhood and write a note about the history you learn from the visits there.

Class 6 History Chapter 10 Ancient India: Cultural Additional Important Questions and Answers

Complete the sentence by choosing the correct option:

Question 1.
______ means a gathering of learned men.
(a) Pitaka
(b) Sangham
(c) Shreni
Answer:
(b) Sangham

Question 2.
The Agamgranthas are a collection of the teachings of ________.
(a) Guru Nanak
(b) Gautam Buddha
(c) Vardhaman Mahavir
Answer:
(c) Vardhaman Mahavir

Question 3.
Vimalsuri has told the story of ____ in Paumchariya a poetic work in Prakrit.
(a) Rama
(b) Harishchandra
(c) Buddha
Answer:
(a) Rama

Question 4.
Tipitaka is written in ______.
(a) English
(b) Pali
(c) Hindi
Answer:
(b) Pali

Question 5.
_______ women composed gathas about their own experience.
(a) Illiterate
(b) Housewives
(c) Learned
Answer:
(c) Learned

Question 6.
The Bhagwad Gita, which is a sacred text of the Hindu, is a part of the ______.
(a) Ramayana
(b) Arthashastras
(c) Mahabharata
Answer:
(c) Mahabharata

Question 7.
Adi Shankaracharya lived during the ______ century CE.
(a) seventh
(b) eighth
(c) ninth
Answer:
(b) eighth

Question 8.
Kautilya wrote the ______.
(a) Arthashastra
(b) Raghuvansha
(c) Brahmasutras
Answer:
(a) Arthashastra

Question 9.
Patanjali wrote _______.
(a) Kumarsambhava
(b) Upanishads
(c) Mahabhashya
Answer:
(c) Mahabhashya

Question 10.
‘Ramayana’ and ‘Mahabharata’ are the two _______ epics of ancient India.
(a) Arsha
(b) Modern
(c) Classical
Answer:
(a) Arsha

Question 11.
Arsha means _______ by rishis or sages.
(a) sung
(b) reported
(c) composed
Answer:
(c) composed

Question 12.
The main character of Ramayana is ________.
(a) Shri Ram
(b) rishis
(c) Kautilya
Answer:
(a) Shri Ram

Question 12.
Mahabharata has been composed by the sage ______.
(a) Kautilya
(b) Vyas
(c) Adi
Answer:
(b) Vyas

Question 14.
India has an ancient tradition of telling a ____ through songs, music and dance.
(a) story
(b) moral
(c) fairytale
Answer:
(a) story

Question 15.
_______ composed by Pandit Vishnusharma is an excellent example of narrative literature.
(a) Champak
(b) Chandamama
(c) Panchatantra
Answer:
(c) Panchatantra

Question 16.
________ was carried out by sea as well as land routes.
(a) Trade
(b) Travel
(c) Study
Answer:
(a) Trade

Question 17.
The concept of stitching clothes was introduced in India during the ______ period.
(a) Vakataka
(b) Kushana
(c) Satavahana
Answer:
(b) Kushana

Question 18.
Jeevaka was a well known ______ at the court of king Bimbisara.
(a) clown
(b) minister
(c) vaidya
Answer:
(c) vaidya

Question 19.
_______ were the first to use the numerals 1 to 9 and zero.
(a) Chinese
(b) Nepalese
(c) Indians
Answer:
(c) Indians

Question 20.
The scientist Aryabhatta wrote the book Aryabhatiya which included many formulae for ______ operations.
(a) mathematical
(b) scientific
(c) medical
Answer:
(a) mathematical

Question 21.
Aryabhatta was also an ________.
a) scientist
(b) astronomer
(c) astrologer
Answer:
(b) astronomer

Question 22.
________ was an important city on the ancient indian trade route.
(a) Nalanda
(b) Vikramshila
(c) Takshashila
Answer:
(c) Takshashila

Question 23.
Emperor Harshavardhan made generous donations to ________University.
(a) Nalanda
(b) Vikramshila
(c) Takshashila
Answer:
(a) Nalanda

Question 24.
Vikramshila University was established by king _______ in the eighth century CE.
(a) Harshavardhan
(b) Dharmapal
(c) Ashoka
Answer:
(b) Dharmapal

Question 25.
During the Pallava dynasty, ________ in Tamil Nadu emerged as an important centre of education.
(a) Nalanda
(b) Valabhi
(c) Kanchi
Answer:
(c) Kanchi

Question 26.
The stone pillars erected by Emperor Ashoka at various places are excellent examples of Indian ________.
(a) sculpture
(b) drawing
(c) photography
Answer:
(a) sculpture

Question 27.
_______ architecture developed during the in South India.
(a) Pillar
(b) Temple
(c) Statue
Answer:
(b) Temple

Question 28.
The art of making ______ images of deities emerged during the period of the Pallavas.
(a) copper
(c) gold
(c) bronze
Answer:
(c) bronze

Question 29.
The ______ pillar at Mehrauli near Delhi is evidence of the advanced knowledge of metallurgy of the ancient Indians.
(a) iron
(b) gold
(c) bronze
Answer:
(a) iron

Answer in one sentence:

Question 1.
In which languages was the ancient Indian literature written?
Answer:
Ancient Indian literature was written in Sanskrit, Ardhamagadhi, Pali and Tamil languages.

Question 2.
What variety was included in the ancient Indian literature?
Answer:
Ancient Indian literature included varieties like religious literature, treatises on grammar, epics, plays, stories, etc.

Question 3.
What does ‘Sangham’ mean?
Answer:
Sangham means a gathering of learned men.

Question 4.
Name two prominent Sangham epics.
Answer:
The two prominent epics are ‘Silappadhikarm’ and Manimekhalai’.

Question 5.
What do we learn from the Sangham literature?
Answer:
From the Sangham literature we learn about the political and social life in south India during the period.

Question 6.
Name the three important religious texts.
Answer:
The important religious texts are Agamgranth, Tipitaka and Bhagwad Gita.

Question 7.
In which languages are the Jain Agamgranth written?
Answer:
The Jain Agamgranthas are written in the Prakrit languages of Ardhamagadhi, Shaurseni and Maharashtri.

Question 8.
What does Agamgranthas contain?
Answer:
Agamgranthas are a collection of the teachings of Vardhaman Mahavir.

Question 9.
Give the literary work of Haribhadrasuri.
Answer:
Haribhadrasuri’s literary work Samaraichchakaha is well known.

Question 10.
What does Sutta Pitaka contain?
Answer:
Sutta Pitaka includes texts of Gautam Buddha’s teachings or sermons.

Question 11.
What instructions are given in Vinay Pitaka?
Answer:
The Vinay Pitaka gives the rules of behaviour which bhikkhus and bhikkhunis in the Bauddha Sangha should follow in their day- to-day lives.

Question 12.
Which is the sacred text of the Hindus?
Answer:
The Bhagvad Gita is the sacred text of the Hindus.

Question 13.
Who wrote the Arthashastra?
Answer:
Kautilya wrote the Arthashastra.

Question 14.
What is Ashtadhyayi?
Answer:
Ashtadhyayi is a treatise in grammar written by the grammarian Panini.

Question 15.
Name the two Arsha of ancient India.
Answer:
Ramayana and Mahabharata are the two ‘Arsha’ epics of ancient India.

Question 16.
What does ‘Arsha’ mean?
Answer:
Arsha means composed by rishis or sages.

Question 17.
Who wrote the Ramayana?
Answer:
Rishi Valmiki composed the Ramayana.

Question 18.
Who wrote the Mahabharata?
Answer:
The Mahabharata has been composed by sage Vyas.

Question 19.
Which literature is an excellent example of narrative literature?
Answer:
Panchatantra composed by Pandit Vishnusharma is an excellent example of narrative literature.

Question 20.
What are shrenis?
Answer:
Organisations of traders and artisans are called shrenis.

Question 21.
When was the concept of stitching clothes introduced in India?
Answer:
The concept of stitching clothes was introduced in India during the Kushana period.

Question 22.
What does Charaka Samhita contain?
Answer:
The Charaka Samhita contains detailed information about clinical diagnosis and pharmacy.

Question 23.
Explain the concept of decimal system.
Answer:
Indians invented the concept of decimal system in which the value of a digit changes according to its place ekam, daham, (units, terms, etc).

Question 24.
Name some of the students who attended the Takshashila University.
Answer:
A famous vaidya, Jeevaka, Chandragupta Maurya, the grammarian Panini and vaidya Charaka are some of the students of the Takshashila University.

Question 25.
Which Chinese scholar visited the Takshashila University?
Answer:
The famous Chinese Bauddha bhikkhu, Fa-hien visited the Takshashila University.

Question 26.
Name the Chinese Bhikkhus that visited Valabhi.
Answer:
Yuan Chwang and Itsing, the Chinese Bauddha Bhikkhus visited Valabhi.

Question 27.
Which emperor made generous donation to Nalanda University?
Answer:
Emperor Harshavardhan made generous donation to Nalanda University.

Question 28.
How could one get admission at the Nalanda University?
Answer:
Students seeking admission to the university had to appear for an examination at the entrance gate.

Question 29.
Who established the Vikramshila University?
Answer:
Vikramshila University was established by a king named Dharmapal in the eighth century

Question 30.
When did Kanchi emerge as an important centre of education?
Answer:
During the reign of the Pallava dynasty, Kanchi in Tamil Nadu emerged as an important centre of education.

Question 31.
How do we know that Indian sculpture was excellent?
Answer:
The stone pillars erected by Emperor Ashoka at various places are excellent examples of Indian sculptures.

Answer in brief:

Question 1.
What is a classical period in history?
Answer:
Sometimes there is such a period in the history of language, literature and art and that its glory remains undiminished even later on such a period is said to be classical.

Question 2.
Explain ‘Theatre’.
Answer:
India has an ancient tradition of telling a story through songs, music and dance. When these arts are presented with supporting dialogues they are known as ‘theatre’.

Question 3.
Give the importance of surgeon Sushruta’s treatise.
Answer:

(a) The famous surgeon Sushruta has discussed the diagnosis of different ailments and their remedies in his treatiste the ‘Sushruta Samhita’.

(b) The importance of this text is that it discusses the different causes leading to injuries, fractures, their types and the various types of surgeries required for them.

Answer the following:

Question 1.
Takshashila University
Answer:
(a) Takshashila was an important city on the ancient Indian trade route.

(b) Gautama Buddha and a famous vaidya, had studied at Takshashila University.

(c) Chandragupta Maurya the founder of the Mauryan Empire was educated at this university.

(d) The Greek historians who accompanied Alexander have also given a description of if the university. They have stated that such a university did not exist anywhere in Greece.

(e) The famous Chinese Bauddha bhikkhu, Fa- Hien who came to India around 400 CE also visited the Takshashila University. The university provided education in various subjects such as Vedic literature, Buddhist philiosophy, economics, logic, etc.

Balbharti Maharashtra State Board Class 6 History Solutions Chapter 9 Ancient Kingdoms of the South Notes, Textbook Exercise Important Questions and Answers.

Maharashtra Board Class 6 History Solutions Chapter 9 Ancient Kingdoms of the South

Class 6 History Chapter 9 Ancient Kingdoms of the South Textbook Questions and Answers

1. Can you tell ?

Question 1.
Whose name did the Satavahana kings write before their own?
Answer:
Jhe Satavahana kings were known to follow the custom of writing their mother’s name before their own.

Question 2.
The ancient name of Kolhapur.
Answer:
The ancient name of Kolhapur was ‘Kuntal’.

2. Complete the table by reading the map in the lesson:

Pallava	Kanchi
	Aihole, Badami, Pattdakal
Satavahana

Answer:

Pallava	Kanchi
Chalukya	Aihole, Badami, Pattdakal
Satavahana	Ajanta, Ellora, Nashik, Bhokardan

3. Tabulate the following names as dynasties and their capitals:
Satavahana, Pandya, Chalukya,Vakataka, Pallava, Madurai, Pratishthan, Kanchipuram, Vatapi
Answer:

Dynasty                                                                     Capital
Satavahana	Pratishthan
Chalukya	Vatapi
Vakataka	Vatsagulm
Pallava	Kanchipuram
Pandya	Madurai

4. Observe any three picture in the lesson and write in your own words what you learn from them:
Answer:
The Kailas Temple:

The Kailas temple at Ellora in Maharashtra was carved out during the reign of Krishna Raja I. This temple is the largest rock-cut monolithic ancient Hindu temple. This temple gets its name Kailas as it symbolizes mount Kailas, the home of Lord Shiva.

A Satavahana coin:

Indian trade was at its zenith during the Satavahana period. Indian goods were exported to western countries and even as far as Rome. Trade took place by sea and this fact is known through coins which have the image of a ship carved on it.

The Ratha or chariot temples:

The rathas or shrines shaped as temple chariot are hewn from the granite rock. They are a perfect example of monilithic rock-cut architecture of the Pallava dynasty. These group monuments at Mahabalipuram has been classified as a UNESCO World Heritage Site.

5. Answer in one sentence:

Question 1.
Name the ancient dynasties of Southern India.
Answer:
The Cher, Pandya and Chola dynasty were the ancient dynasties of Southern India.

Question 2.
After the decline of the Mauryan Empire which local kings became independent?
Answer:
After the decline of the Mauryan Empire, the local kings in Maharashtra, Andhra Pradesh, Karnataka became independent.

6. Anwer in brief:

Question 1.
Write about the achievements of Mahendra Varman.
Answer:

• Mahendra Varman was an able Pallava ruler.
• He expanded the Pallava kingdom.
• He was also a playwright.

Question 2.
What is meant by Tri-samudra-toya-peet- vahnah?
Answer:
Tri-samudra-toya-peet-vahnah means ‘one whose houses have drunk the water of three seas’. It simply means to describe the one whose kingdom is so vast that it extends to the three seas, i.e. Arabian sea, the Bay of Bengal and the Indian Ocean.

Question 3.
What goods were exported from the Muziris port?
Answer:
Goods like spices, pearls, precious stones were exported from the Muziris port.

Activity:

Make a collection of the pictures in the chapter and display them in the school exhibition

Class 6 History Chapter 9 Ancient Kingdoms of the South Additional Important Questions and Answers

Complete the sentence by choosing the correct option:

Question 1.
Muziris is mentioned as an important port on the coast of _______.
(a) Kerala
(b) Tamil Nadu
(c) Chennai
Answer:
(a) Kerala

Question 2.
Muziris port was in the ______ Kingdom and was a major centre for export.
(a) Chola
(b) Pandya
(c) Cher
Answer:
(c) Cher

Question 3.
The Pandya kingdom was a part of today’s ______.
(a) Karnataka
(b) Tamil Nadu
(c) Maharashtra
Answer:
(b) Tamil Nadu

Question 4.
The capital of the Pandya kingdom was ______.
(a) Kodaikanal
(b) Maharashtra
(c) Madurai
Answer:
(c) Madurai

Question 5.
After the decline of the Mauryan Empire, the local kings in Maharashtra, Andhra Pradesh Karnataka also became _____.
(a) independent
(b) dependent
(c) republic
Answer:
(a) independent

Question 6.
Pratishthan or the present day Paithan in ______ was the capital of Satvahana Dynasty.
(a) Delhi
(b) Maharashtra
(c) Andhra Pradesh
Answer:
(b) Maharashtra

Question 7.
King Simuk was the founder of the _______ dynasty.
(a) Satavahana
(b) Vakataka
(c) Chalukya
Answer:
(a) Satavahana

Question 8.
The inscription in the _______ caves near Junnar in Pune district bear the names of the important persons of this dynasty.
(a) Kanheri
(b) Kolhapur
(c) Naneghat
Answer:
(c) Naneghat

Question 9.
Of the ________ Kings, Gautamiputra Satakarni is particularly well known.
(a) Chalukya
(b) Satavahana
(c) Vakataka
Answer:
(a) Chalukya

Question 10.
Satakarni defeated the _________ king Nahpana.
(a) Shaka
(b) Cher
(c) Paithan
Answer:
(a) Shaka

Question 11.
The famous poetic work Gatha-Saptashati in Maharashtri, was ________ by the Satavahana king Hala.
(a) composed
(b) edited
(c) sung
Answer:
(a) composed

Question 12.
Indian trade ________ greatly during the Satavahana period.
(a) decreased
(b) increased
(c) receded
Answer:
(b) increased

Question 13.
Paithan, Ter, Bhokardan, Kolhapur were recognised as important centres of ________.
(a) music
(b) culture
(c) trade
Answer:
(c) trade

Question 14.
Indian goods were exported as far away as ________.
(a) America
(b) Rome
(c) Sri Lanka
Answer:
(b) Rome

Question 15.
The cave sculptures at Ajanta, Nashik, Karla, Bhaje, Kanheri, Junnar in Maharashtra were carved during the ______ period.
(a) Satavahana
(b) Vakataka
(c) Cher
Answer:
(a) Satavahana

Question 16.
The power of the Satavahanas began to _______ by the third century CE.
(a) strengthen
(b) weaken
(c) flourish
Answer:
(b) weaken

Question 17.
Among the dynasties that emerged after the Satavahana period was the Vakataka, a _______ dynasty.
(a) powerful
(b) varied
(c) dynamic
Answer:
(a) powerful

Question 18.
The Vakataka dynasty was founded by _____.
(a) King Pravarsen
(b) King Pulakeshi
(c) King Vindhyashakti
Answer:
(c) King Vindhyashakti

Question 19.
King Vindhyashakti was ______ by Pravarsen I.
(a) succeeded
(b) finalised
(c) demoralised
Answer:
(a) succeeded

Question 20.
Chandragupta II had married his daughter Prabhavati to _________, the Vakataka king.
(a) Dantidurg
(b) Setubandh
(c) Rudrasen II
Answer:
(c) Rudrasen II

Question 21.
Varahdev, a minister of the Vakataka king Harishen, was a follower of _______.
(a) Judaism
(b) Buddhism
(c) Elinduism
Answer:
(b) Buddhism

Question 22.
Kalidasa’s ______ also belongs to the Vakataka period.
(a) Meghadoot
(b) Setubandh
(c) Saptashati
Answer:
(a) Meghadoot

Question 23.
The Chalukya dynasty in _____ was a powerful one.
(a) Sri Lanka
(b) Karnataka
(c) Nepal
Answer:
(b) Karnataka

Question 24.
Pulakeshi I established the rule of the Chalukya Ancient Kingdoms of the South dynasty in the _______ century CE.
(a) fourth
(b) fifth
(c) sixth
Answer:
(c) sixth

Question 25.
The famous temples at Badami, Aihole and Pattadakal were built during the _______ period,
(a) Vakataka
(b) Satavahana
(c) Chalukya
Answer:
(c) Chalukya

Question 26.
The Pallavas were also powerful dynasty in ______ India.
(a) South
(b) North
(c) East
Answer:
(a) South

Question 27.
_______ in Tamil Nadu was the capital of the Pallava dynasty.
(a) Mahabalipuram
(b) Kanchipuram
(c) Ellora
Answer:
(b) Kanchipuram

Question 28.
Mahendra Varman was an able _______ ruler.
(a) Chalukya
(b) Pallava
(c) Vakataka
Answer:
(b) Pallava

Question 29.
The famous ‘ratha’ temples of ________ were sculpted during the reign of Mahendra Varman.
(a) Maharashtra
(b) Kaniyakumari
(c) Mahabalipuram
Answer:
(c) Mahabalipuram

Question 30.
The Pallavas had a powerful and well equipped ______.
(a) army
(b) navy
(c) airforce
Answer:
(b) navy

Question 31.
The Rashtrakuta dynasty was first established in ______ by king Dantidurg.
(a) Mahabalipuram
(b) Nepal
(c) Maharashtra
Answer:
(c) Maharashtra

Question 32.
Krishna Raja I had the famous Kailas temple carved at _______.
(a) Ellora
(b) Ajanta
(c) Kanheri
Answer:
(a) Ellora

Answer in one sentence:

Question 1.
Name the ancient dynasties of Southern India.
Answer:
The Cher, Pandya and Chola dynasty were the ancient dynasties of Southern India.

Question 2.
Which ancient port is mentioned as an important port?
Answer:
‘Muziris, is mentioned as an important port on the coast of Kerala.

Question 3.
What was the capital of the Paridya kingdom?
Answer:
The capital of the Pandya kingdom was Madurai.

Question 4.
What was the capital of the Satavahana dynasty?
Answer:
Pratishthan or the preseht day Paithan in Maharashtra was the capital of the Satavahana dynasty.

Question 5.
Who was the founder of the Satavahana dynasty?
Answer:
iCing Simuk was the founder of the Satavahana dynasty.

Question 6.
Which custom did the Satavahana kings follow?
Answer:
The Satavahana kings were known to follow the custom of writing their mother’s name before their own.

Question 7.
Name a popular Satavahana king.
Answer:
Gautamiputra Satakarni was a very well known Satavahana king.

Question 8.
What title was given to Gautamiputra Satakarni?
Answer:
Gautamiputra Satakarni was awarded the title Tri-samudra-toya-peet-vahan’.

Question 9.
Give the extent of the Satavahana empire.
Answer:
The Satavahana empire extended from the river Narmada in the north to the Tunga- bhadra river in the south.

Question 10.
Name the trade centres of the Satavahana period.
Answer:
Paithan, Ter, Bhokardan, Kolhapur were recognised as important trade centres of the Satavahana period.

Question 11.
Which caves were sculpted during the Satavahana period?
Answer:
The Caves at Ajanta, Nashik, Karla, Bhaje, Kanheri, Junnar in Maharashtra were carved during the Satavahana period.

Question 12.
Which dynasty emerged after the Satavahan dynasty?
Answer:
The Vakataka dynasty emerged after the Satavahana dynasty.

Question 13.
Who founded the Vakataka dynasty?
Answer:
The Vakataka dynasty was founded by king Vindhyashakti.

Question 14.
What did the Vakataka king, Pravarsen II compose?
Answer:
The Vakataka king Pravarsen II composed ‘Setubandh’ in Maharashtra.

Question 15.
What was the name of Kalidasa’s literature?
Answer:
Kalidasa’s literature was ‘Meghdoot’.

Question 16.
Which powerful dynasty was from Karnataka?
Answer:
The Chalukya dynasty was a powerful dynasty from Karnataka.

Question 17.
Name the capital of the Chalukya dynasty.
Answer:
Badami or Vatapi was the capital of the Chalukya dynasty.

Question 18.
Name the temples built during the Chalukya period.
Answer:
The famous temples at Badami, Aihole and Pattadakal were built during the Chalukya period.

Question 19.
Which powerful dynasty existed in South India?
Answer:
The Pallavas were a powerful dynasty in South India.

Question 20.
Name the capital of the Pallava Kingdom.
Answer:
Kanchipuram in Tamil Nadu was the capital of the Pallava kingdom.

Question 21.
What is characteristic of the ‘ratha’ temples?
Answer:
The ‘ratha’ temples of Mahabalipuram are characteristic to have been sculpted from a single rock.

Question 22.
Write Yuan Chwang’s opinion about the Pallava kings.
Answer:
Yuan Chwang visited Kanchi and recorded that people of all religions received tolerant and just treatment under the rule of the Pallava kings.

Question 23.
Who was the founder of the Rashtrakuta Dynasty?
Answer:
King Dantidurg was the founder of the Rashtrakuta Dynasty.

Question 24.
Who sculpted the Kailas temple at Ellora?
Answer:
Krishna Raja I had the famous Kailas temple carved at Ellora.

Answer in brief:

Question 1.
Describe the work of literature by king Hala.
Answer:
The Satavahana king Hala composed the famous poetic work Gatha-Saptashati in Maharashtrin a Prakrit language.
This work provides information about the life of the people during the Satavahana period.

Balbharti Maharashtra State Board Class 10 Marathi Solutions Kumarbharti Chapter 1 जय जय हे भारत देशा Notes, Textbook Exercise Important Questions and Answers.

Maharashtra State Board Class 10 Marathi Kumarbharti Chapter 1 जय जय हे भारत देशा

शब्दार्थ

तपोवन – तपस्व्यांचे वास्तव्य असणारे वन. उजळली – प्रकाशमय झाली. उपनिषदे – वेदांचे सार. नररत्ने – वीरपुरुष, देशभक्त. खाण – भांडार. युग – काही शतकांचा कालखंड. धैर्य – धाडस, हिंमत. छळ – जुलूम. नच – नाहीच. वाकल्या माना – शरणागत. कापरे – भीती. अभिमान – सार्थ गर्व. आत्मशक्ती – स्वबळ, मनाची शक्ती. त्याग – सोडणे. श्रम – कष्ट, मेहनत. धुंद – आनंदाने बेभान. हरित क्रांती – धनधान्याची विपुलता. विश्वशांती – जगामध्ये शांतता नांदणे. कंगाल – दरिद्री. थरारल्या – शहारल्या. झळकत – प्रकाशत. मशाल – मोठी ज्योत. लोकशक्ती – लोकांची एकजूट, एकता. दलितमुक्ती – पीडितांची शोषणापासून सुटका.

कवितेचा (गीताचा) भावार्थ

हे माझ्या प्रिय भारत देशा, तुझा जयजयकार असो! तू नवीन जगाची आशा आहेस.

तपोवनातून उपनिषदांतील तत्त्वज्ञानाची भाषा प्रकाशमय झाली. तुझ्या मातृभूमीत शूरवीर पुरुषांच्या खाणी जन्माला आल्या; उदयाला आल्या. युगानुयुगे तू जगाला धैर्याची शिकवण दिली आहेस. तू नवीन सूर्याचा तेजस्वी देश आहेस. तू नवीन जगाची प्रेरणा आहेस. तुझा जयजयकार असो.

जुलूम-जबरदस्तीपुढे, मारक शक्तीपुढे आणि छळ करणाऱ्या व्यवस्थेपुढे तू कधी वाकला नाहीस, शरण आला नाहीस. तुझा शूर पराक्रमी स्वाभिमान पाहून अन्यायालाही भीतीचे कापरे भरते. अन्यायाला धडकी भरते. हे आत्मबळाच्या देशा, हे त्यागाच्या नि भक्तीच्या देशा, तुझा विजय असो. तू नवीन जगाची आस आहेस, तुझा जयजयकार असो.

घाम गाळून, कष्ट करून पिकलेली शेते आनंदाने बेहोश होऊन डोलत आहेत. घामाच्या थेंबांतून शेतकऱ्याच्या हृदयातील आनंद ओसंडतो आहे. तू हरितक्रांतीचा देश आहेस, तू विश्वामध्ये शांती नांदवणारा देश आहेस, तुझा विजय असो. तू नवीन जगाची आशा आहेस. हे भारत देशा, तुझा जयजयकार असो.

दैन्य-दारिद्र्याच्या घोर अन्यायाला जाळणाऱ्या मशाली आता पेटून झळाळत आहेत. त्यामुळे भोवताली भुकेकंगालांच्या झोपड्या आनंदाने शहारत आहेत. जनतेची एकजूट असलेल्या, हे लोकशक्तीच्या देशा, तुझा विजय असो. सर्व शोषित-पीडित जनांच्या मुक्तीचा तू देश आहेस. तू नव्या जगाची एकमेव आशा आहेस. हे भारत देशा, तुझा बुलंद जयजयकार असो.

Balbharti Maharashtra State Board Class 8 Science Solutions Chapter 17 Man-made Materials Notes, Textbook Exercise Important Questions and Answers.

Maharashtra State Board Class 8 Science Solutions Chapter 17 Man-made Materials

Class 8 Science Chapter 17 Man-made Materials Textbook Questions and Answers

1. Try to find it:

Question a.
Plastic shows …………. property, hence it can be moulded to any shape.
Answer:
Plastic shows plasticity property, hence it can be moulded to any shape.

Question b.
Motor cars are coated with ……… .
Answer:
Motor cars are coated with Teflon.

Question c.
Thermocol melts at ………… °C.
Answer:
Thermocol melts at more than 100 °C (it is about 240 °C).

Question d.
…………….. glass dissolves in water.
Answer:
Alkali silicate or water glass dissolves in water.

2. Who is my partner?

Question a.

Column ‘A’	Column ‘B’
1. Lead glass	a. Plates
2. Bakelite	b. Mattresses
3. Thermocol	c. Electric bulb
4. Optic glass	d. Electric switch
5. Polypropylene	e. Lens

Answer:

Column ‘A’	Column ‘B’
1. Lead glass	c. Electric bulb
2. Bakelite	d. Electric switch
3. Thermocol	a. Plates
4. Optic glass	e. Lens
5. Polypropylene	b. Mattresses

3. Answer the following.

Question a.
Thermocol is produced from which material?
Answer:
Thermocol is made from polystyrene which is also a complex thermoplastic substance.

Question b.
Write uses of PVC.
Answer:
PVC or Polyvinyl chloride is used for making bottles, raincoat, pipes, handbags, shoes, electric cable insulation, furniture, ropes, toys, etc.

Question c.
Write the natural or man-made raw material of the following items.
Mattress, beaker, bangle, chair, gunny bag, broom, knife, pen.
Answer:

Items	Natural raw material	Man-made raw materials
Mattress	Cotton, Coir (Jute fibres)	Polypropylene
Beaker	___	Glass (Silicate or borosilicate glass)
Bangle	Gold, silver, lac, copper	Plastic, Glass
Chair	Wood	Plastic (PVC)
Gunny bag	Jute, cotton	Plastic (PVC)
Broom	Plant fibres	Plastic fibres (PVC)
Knife	Metals such as iron	Plastic
Pen	Metals	Plastic

Question d.
Which are the main ingredients of glass?
Answer:
The main ingredients of glass are sand and silica.

Question e.
How the plastic is produced?
Answer:

1. Plastics are derived from natural materials such as natural gas, oil, coal, minerals and plants.
2. The first synthetic plastics were i derived from cellulose, a substance found in plants and trees. This cellulose was heated with chemicals and resulted in a plastic like material.
3. In modern times, the different raw materials are used for making plastics, but most plastics are made from the hydrocarbons present in the natural gas, oil and coal.
4. Plastics are simply chains of like molecules linked together. These chains are called polymers. Thus, many plastics begin with “poly,” such as polyethylene, polystyrene and polypropylene.
5. These polymers are made of carbon and hydrogen and sometimes oxygen, nitrogen, sulphur, chlorine, fluorine, phosphorous or silicon.
6. Plastic is produced in factories by suitable chemical reactions.

4. Distinguish between. 

Question a.
Man-made material and natural material
Answer:

Man-made material	Natural material
1. The man-made materials are obtained from processes in scientific laboratory.	1. Natural materials are obtained from nature.
2. Man-made materials are subjected to rigorous processing to alter the material for serving the intended purpose.	2. Natural materials are subjected to less treatment and processing.
3. Man-made materials are typically much more durable having a very long lifespan.	3. Natural materials have shorter lifespan, because these materials were once alive and so gradually perish over time.
4. Maintaining man-made materials require less care and attention.	4. Maintaining natural materials requires lots of care and continuous attention.
5. Man-made materials can have a negative environmental impact because they are not sustainable. E.g. Glass, plastic, Thermocol, soil, metals, rubber.	5. Natural materials do not have a negative environmental impact because they can be degraded easily. E.g. Cotton, silk, wood.

Question b.
Thermoplastic and Thermosetting plastic:
Answer:

Thermoplastic	Thermosetting plastic
1. The plastic that can be moulded as per our wish is called thermoplastic.	1. The plastic in which a specific shape is given with the help of mould and this shape cannot be changed again on heating is called thermosetting plastic.
2. Thermoplastic substances can be recycled and reused. E.g. PVC – Polyvinyl chloride, PS – Polystyrene, PE – Polyethylene and PP – Polypropylene are types of thermoplastics.	2. Thermosetting plastic cannot be reused again. E.g. Bakelite, Melamine, Polyurethane and polyster are the types of thermosetting plastics.

5. Answer the following in your own words.

Question a.
Explain the effect of following materials on environment and human health.
1. Plastic
2. Glass.
3. Thermocol.
Answer:
1. Plastic:

1. Plastic is non-degradable substance. Hence if thrown in any ecosystem, it remains unchanged for many years.
2. It is one of the worst environmental pollutants as its disposal is a major problem.
3. If thrown in water bodies, it affects the aquatic animals. Many of turtles mistake it for algae and eat the plastic. Eventually such animals die due to choking.
4. In terrestrial environment, the grazing animals like cattle are affected due to plastic.
5. If burnt it emits very toxic gases.
6. In landfill sites, it remains unchanged for thousands of years.

2. Glass:

1. The glass production is carried out at high temperatures of about 1500 °C. This burning emits many hazardous gases like sulphur dioxide, nitrogen dioxide, carbon dioxide. These gases cause the greenhouse effect.
2. Moreover, glass being non-degradable, cause pollution.
3. If broken glass pieces or any waste glass material is disposed into aquatic environment, it affects animals and plants.
4. Similarly, glass pieces block the drainages.
5. The waste glass thrown anywhere cause injury to terrestrial fauna.

3. Thermocol:

1. Thermocol contains carcinogenic ingredients in the form of styrene. If there is prolonged contact with thermocol, there is a possibility of blood cancer like leukemia and lymphoma.
2. Thermocol is non-degradable. It cannot be degraded into harmless substances easily.
3. If it is burnt for destruction, it releases toxic gases in atmosphere.
4. The plates and cups used for food, water, tea, etc. are made up of thermocol. This may affect the health. Reheating the food kept in thermocol releases styrene. This styrene may dissolve in that food, causing health problems like cancer.

Question b.
Which measures will you arrange to minimize the environmental problems arising due to non-degradable plastic?
Answer:

1. The use of plastic should be minimum. Reducing the consumption, reusing the same plastic again and again, recycling the used plastic and making some new products from the used plastic are some of the measures that can be adopted.
2. There are attempts to use plastic in making roads. Therefore, plastic is bought with good price at some places.
3. Therefore, instead of disposing of it anywhere, it should be collected and sold in best possible way.
4. The better alternatives for plastic should be adopted.
5. The awareness programmes about misuse of plastic should be arranged so that common man can understand the dangers of using plastic.

6. Write short notes. 

Question a.
Glass production:
Answer:
The general preparation of the glass is as follows:

1. Mixture of sand, soda, lime and small quantity of magnesium oxide is heated in furnace.
2. At 1700 °C sand or silicon dioxide melts.
3. To make the mixture melt at lesser temperature, pieces of discarded glasses are added to it.
4. This addition makes the mixture to melt at lesser temperature of 850 °C.
5. When all the ingredients of mixture are liquified, then again it is heated up to 1500 °C.
6. This heating is immediately followed by cooling.
7. The sudden cooling causes the mixture to become homogeneous, amorphous and transparent instead of crystalline.
8. For variety of glass types, different proportions of ingredients are used for heating.

Question b.
Optic glass:
Answer:

1. Optic glass or optical glass needs to be very clear and transparent as it is used in spectacles, lenses and other devices like microscopes.
2. Optic glasses are produced from the mixture of sand, soda, limestone, barium oxide and boron.

Question c.
Uses of plastic:
Answer:
Plastic, the man-made material is used in various forms in modern age. According to the type of plastic, its uses are different.

I. Thermoplastic materials are used for manufacturing following articles:

1. Polyvinyl chloride or PVC is used to make bottles, raincoat, pipes, handbags,: shoes, electric cable insulation, furniture, ropes, toys, etc.
2. Polystyrene is used in making thermo insulating parts of electric appliances like refrigerators, gears of machines, toys, protective coverings like covers of CD and DVD, etc.
3. Polyethylene (PE) plastics are used for making milk bags, packing bags, flexible garden pipes, etc.
4. Polypropylene (PP) is used in making parts of loudspeakers and vehicles, ropes, mattresses, laboratory appliances, etc.

II. Thermosetting plastic is used in the manufacturing of the following items:

1. Bakelite for making cabinets of radio, T.V., telephones, electric switches, toys, plastic handles of cookers, etc.
2. Melamine for making domestically useful items like cup – saucers, plates, tray, some spare parts of airplane engines, electric and sound insulating coverings, etc.
3. Polyurethane in making surfing boards, small boats, furniture, seats in vehicles, etc.
4. Polyester in fibreglass, toners of laser printers, textile industry, etc.

Can you tell?

Question 1.
Make a list of 20 different man-made materials present in your home, school and places around and discuss.
Answer:
Schoolbag, books, computer, table lamp, tube lights, benches, shoes, dress, pencil, pen, tiffin box, water bottle, raincoat, umbrella, medicine tablets, pen drive, chalk, duster, utensils, gas burner, biscuits.

Can you recall?

Question 1.
How many plastic carry bags are brought in your home in a day? What happens to those later on?
Answer:
Till May 2018 about one or two plastic bags were brought in our home every day. But now due to prohibition on plastic bags and other plastic items by the Government, the use of plastic has been drastically reduced. The bags brought at home caused lot of plastic pollution. Plastic is non-biodegradable, thus it always created problem of their disposal.

If dumped in a water body, it can be hazardous for aquatic animals. If thrown in the garbage, plastic articles find their way to landfilling areas. If thrown anyhow plastic may be consumed by stray animals. This causes toxic effects on them. If burnt they emit toxic gases.

Question 2.
How are the used up and thrown away carry bags, water bottles, milk bags recycled?
Answer:
The plastic waste is collected by the kabadiwala or sweepers. They sell these articles to the recycling units. In recycling units, the recycling of some of the plastic items is done. This leads to formation of plastic of low quality which may be used in making some newer plastic items.

Question 3.
Which material is wrapped around the items of glass or similar material during transport to prevent from breaking up?
Answer:
The plastic bubble wrap or thermocol is used to protect fragile items from the shocks and breaks during their transport.

Project:

Question 1.
Collect the information about the plastic used in production of utensils used in microwave oven.

Question 2.
Collect the information about the material used in production of denture. (A set of artificial teeth)

Class 8 Science Chapter 17 Man-made Materials Important Questions and Answers

Try to find it:

Question 1.
The plastic that can be moulded as per our wish is called …………… .
Answer:
The plastic that can be moulded as per our wish is called thermoplastic.

Question 2.
…………… is a type of plastic used for manufacturing artificial teeth.
Answer:
Polyacrylic is a type of plastic used for manufacturing artificial teeth.

Question 3.
Thermocol is a form of a complex material called ……………. .
Answer:
Thermocol is a form of a complex material called polystyrene.

Write whether the following statements are True or False: Rewrite the false statements after correcting:

Question 1.
Plastics are inorganic polymers that show plasticity.
Answer:
False. (Plastics are organic polymers that show plasticity.)

Question 2.
Polythene, PVC are thermosetting plastic materials.
Answer:
False. (Polythene, PVC are thermoplastic materials.)

Question 3.
Plastic is bad conductor of heat and electricity.
Answer:
True.

Question 4.
Surfing boards are made up of bakelite.
Answer:
False. (Surfing boards are made up of polyurethane.)

Question 5.
Being bad conductor of electricity, glass is used as insulator in electric appliances.
Answer:
True.

Match the columns:

Question 1.

Column A	Column B
1. Borosilicate glass	a. Oxide of specific metal.
2. Alkali silicate glass	b. Sand, soda, limestone, barium oxide and boron.
3. Lead glass	c. Sand and soda.
4. Optical glass	d. Sand, soda, limestone and lead oxide.
5. Coloured glass	e. Sand, soda, boric acid and aluminium oxide.

Answer:

Column A	Column B
1. Borosilicate glass	e. Sand, soda, boric acid and aluminium oxide.
2. Alkali silicate glass	c. Sand and soda.
3. Lead glass	d. Sand, soda, limestone and lead oxide.
4. Optical glass	b. Sand, soda, limestone, barium oxide and boron.
5. Coloured glass	a. Oxide of specific metal.

Find the odd one out:

Question 1.
Bakelite, Melamine, Polystyrene, Polyester.
Answer:
Polystyrene (All others are thermosetting plastic materials, polystyrene is thermoplastic.)

Question 2.
Polyvinyl chloride, Polystyrene, Polypropylene, Polyurethane.
Answer:
Polyurethane (All others are thermoplastic materials, polyurethane is thermosetting plastic.)

Question 3.
Vegetable peels, Cotton bolls, Wooden scraps, Plastic bag.
Answer:
Plastic bag (All others are degradable materials, plastic is non-degradable.)

Question 4.
Teflon, Polyacrylic, Fibreglass, Polyester.
Answer:
Fibreglass (All others are types of plastic.)

Considering the relationship in the first pair, complete the second pair:

Question 1.
Processed glass: Fen glass : : Alkali silicate glass : ………..
Answer:
Water glass

Question 2.
Ferrous oxide: Bluish green glass : : Copper oxide : ……..
Answer:
Red glass

Question 3.
Lens : Optical glass : : Laboratory glassware : ……….
Answer:
Silica glass

Question 4.
Light bulbs, Tubes: Lead glass : : Medicine storing : ………
Answer:
Borosilicate glass

Question 5.
Glass: Mixture of silica and silicate : : Thermocol : ………..
Answer:
Polystyrene.

Distinguish between:

Question 1.
Degradable and Non-degradable substances:
Answer:

Degradable substances	Non-degradable substances
1. The substances which can be naturally reduced into their inorganic constituents are called degradable substances.	1. The substances that cannot be degraded on their own into their inorganic constituents are called non-degradable substances.
2. Degradable substances are not accumulated in the nature.	2. Non-degradable substances remain accumulated in the nature for a long time.
3. Degradable substances emit foul odour when they are being decomposed.	3. Non-degradable substances may not emit foul odour as they are not degraded. But they make the place look dirty.
4. Usually microorganisms play a part in the degradation process, hence such substances are also called biodegradable. E.g. Vegetables, fruits, wood, cotton or wool fibres, etc.	4. Microorganisms cannot act on non-degradable substances and hence they are also called non-biodegradable substances. E.g. Plastic, thermocol, glass, metals, etc.

Write short notes:

Question 1.
Properties of plastic:
Answer:

1. Plastic is non-corrosive.
2. It is non-degradable as it does not decompose.
3. The factors such as humidity, heat, rain, etc. do not affect plastic.
4. Any coloured item can be manufactured from plastic.
5. Plastic shows property of plasticity. Thus it can be moulded into any shape that is needed.
6. Plastic is a bad conductor of heat and electricity.
7. Plastic is light-weight and thus preferred for carrying.

Question 2.
Properties of Glass:
Answer:
The glass becomes soft on heating and thus can be moulded into desired shape.

1. According to ingredients added at the time of preparation of glass, its density changes accordingly.
2. Glass is slow conductor of heat. If a cold glass is quickly heated, it cracks suddenly. Similarly, the warm glass if exposed to sudden cooling, it too cracks.
3. Glass is a bad conductor of electricity. Therefore, it is used as insulating material in electric appliances.
4. Glass is transparent, allowing most of light to pass through it. If there are chromium, vanadium or iron oxides in the glass, large amount of light is absorbed in glass.

Answer the following questions in one sentence only:

Question 1.
What is the use of plastic in healthcare sector?
Answer:
Saline bottles, pouches, blood bags, syringes and medicine bottles are made up of plastic, making plastic irreplaceable in the healthcare sector.

Question 2.
Which material is used in coating of vehicles? Why?
Answer:
Teflon is used for coating the vehicle as it protects the vehicles from scratches.

Question 3.
What is the use of polyacrylic type of plastic?
Answer:
Polyacrylic plastic used for manufacturing lenses and in the manufacture of artificial teeth.

Question 4.
What is 4R principle?
Answer:
The 4R principle is the way of behaviour that prevents or lessens the environmental pollution. The 4Rs are Reduce, Reuse, Recycle and Recover.

Question 5.
What are the eco-friendly options for a plastic bag?
Answer:
Jute bag, cloth bag and reusable bags of any natural materials are the eco-friendly options for the plastic bag.

Question 6.
How is Borosilicate glass produced?
Answer:
Borosilicate glass is produced by melting the mixture of sand, soda, boric acid and aluminium oxide.

Question 7.
When is large amount of light absorbed in the glass?
Answer:
If there are oxides of either chromium, vanadium or iron in the glass, large amount of light is absorbed in it.

Give scientific reasons:

Question 1.
It is harmful to eat food kept in thermocol.
Answer:
Thermocol is made up from polystyrene. It is carcinogenic (cancer causing) substance. When food kept in r thermocol containers is reheated, this , styrene dissolves in it. This may affect the r health of the person who consumes such food. It has been noted that there is a great possibility of blood cancer like leukaemia r and lymphoma if one remains in contact with thermocol for a longer time. Thus, it is harmful to eat food kept in thermocol.

Question 2.
Vessels used to cook food in the microwave oven are made up of plastic.
Answer:
The vessels made from metals cannot be used in the microwave oven. The microwaves cannot penetrate steel and so ‘ can only heat the contents through the open top. Some metals cause sparking with microwaves. Microwave energy is absorbed differently by different materials. Plastics of only certain kind are more suitable to be used in the microwave oven.

Answer the following:

Question 1.
What are the qualities of thermocol?
Answer:

1. Thermocol is modern man-made material made from polystyrene.
2. It can be transformed into liquid state when heated at more than 100 °C temperature. On cooling, it returns to the solid state.
3. Therefore, any desired shape can be given to it.
4. It acts as a good shock-absorber and hence used as a packing material to transport brittle material.
5. It is a bad insulator of heat and hence used for storing fish and other perishable articles in market.

Think about it:

Question 1.
Why are the plastic tanks used for storage of chemicals?
Answer:
Plastic is non-corrosive. It is comparatively non-reactive and it does not decompose. Moreover, the plastic containers are easier for handling. They are lighter and unbreakable. Hence the plastic tanks are used for storage of chemicals.

Question 2.
Why most of domestically useful items are replaced by plastic?
Answer:
Plastic is lighter and unbreakable. The handling thus becomes easier. It is non-corrosive, hence pickles, spices, etc. can be stored in plastic containers. It is cheaper as compared to the metal and glass articles. Thus, it becomes popular with general public. It is easier to wash and maintain the plastic articles. These are some of the reasons of making plastic a domestically useful material.

Collect information:

Question 1.
To prevent the degradation due to sunlight, some materials are stored in which type of bottles?
Answer:

The amber glass or brown coloured glass bottles are used to store the materials that may get degraded due to sunlight. This colour prevents the ultraviolet rays of the sun to enter the bottle and bring about chemical changes in the materials. Especially, for sensitive medicines, brown glass bottles are used.

Question 2.
Which type of glass is used in vehicles to avoid injuries in accidents?
Answer:
Front and rear doors have tempered glass. The windshield has laminated safety glass. Even if the accident takes place the glass pieces do not injure the passengers. Laminated safety glass combines two curved glass sheets and a plastic lamina between the two layers of the glass.

This glass is tough and protective. Tempered glass on the other hand is toughened glass which is processed by controlled thermal or chemical treatments. Upon breaking, the tempered glasses crumble into small granular chunks instead of splintering into sharp glass pieces. This prevents the injuries.

Sketch and label the diagram of glass manufacturing process:

Open-Ended Questions:

Question 1.
Classify and make a chart of the materials used in various items in house. Make additions to that chart with reference to various materials.

Answer:

Question 2.
Make list about use of thermocol in your daily life.
Answer:

1. Decorative items used at the time of festivals.
2. Packing materials.
3. Insulating boxes to keep food warm.
4. Insulating boxes to keep fish in iced condition to prevent decomposition.
5. Thermocol beads in the bean bags.

Balbharti Maharashtra State Board Class 7 Science Solutions Chapter 9 Heat Notes, Textbook Exercise Important Questions and Answers.

Maharashtra State Board Class 7 Science Solutions Chapter 9 Heat

Class 7 Science Chapter 9 Heat Textbook Questions and Answers

Fill in the blanks:

Question a.
Maximum heat is absorbed by a ………….. coloured object.
Answer:
black

Question b.
……………. of heat does not require a medium.
Answer:
Radiation

Question c.
Conduction of heat takes place through a ……………. substance.
Answer:
solid

Question d.
The shining surface in a thermos flask decreases the outgoing heat by ……………… .
Answer:
reflection

Question e.
Cooking utensils are made from metals due to their property of ……………… .
Answer:
conduction

Question f.
The earth receives heat from the sun by ………………. .
Answer:
radiation

2. What will absorb heat?
Steel spoon, wooden board, glass vessel, iron griddle (lava), glass, wooden spoon, plastic plate, soil, water, wax.

Question a.
What will absorb heat?
Steel spoon, wooden board, glass vessel, iron griddle (lava), glass, wooden spoon, plastic plate, soil, water, wax.
Answer:
Following will absorb heat fast: steel spoon, iron griddle, water, wax. Remaining objects also obsorb heat but very slowly.

3. Write Answers to the following questions. 

Question a.
How does a fever get lowered by putting a cold compress on the forehead of a patient?
Answer:
The water in the cold compress will evaporate by the heat of fever thus taking some local heat of the body and temperature of the body is lowered, therefore the fever gets lowered by putting a cold compress on the forehead of a patient.

Question b.
Why are the houses in Rajasthan painted white?
Answer:
Rajasthan being a desert, temperature is very high. So there is excess heat. White colour doesn’t absorb the heat but reflects back, so houses will not become hot due to excess heat and inside of the house will be cool. So the houses in Rajasthan are painted white.

Question c.
What are the modes of heat transfer?
Answer:
There are three modes of heat transfer:

1. conduction
2. convection
3. radiation.

Question d.
Explain which mode of heat transfer causes sea breezes and land breezes?
Answer:

1. Unequal heating of air above the sea and land sets up convection currents which cause sea breezes during the day time.
2. The land near the sea is heated by sunlight to a higher temperature than the sea.
3. As the air above the land is heated, it becomes lighter and moves upwards, its place is then taken by cooler air moving from the sea towards the land.
4. Sea breezes are thus set up. At night, the land cools faster than water in the sea. Therefore air above sea water is hotter than air above the land.
5. So cooler air from the land moves towards the sea forming land breeze.

Question e.
Why is the outer coat of the penguins of Antarctica black?
Answer:
The outer coat of the penguins of Antarctica is black because black colour absorbs heat so penguins get lots of heat due to this black colour and they can live easily in very, very cold Antarctica region.

Question f.
Why are heaters fitted near the floor and air conditioners near the ceiling of a room?
Answer:
1. Due to air conditioners, air becomes cool so its density increases and it becomes heavy. So it goes down and warm air with less density comes up and take the place of cold air. This cycle goes on and on and the whole room becomes cool.
2. If it is fitted near the floor then cool air of high density can’t go up and upper air with low density cannot come down and cooling of the room does not take place properly so air conditioners are fitted near the ceiling of a room.
3. Heaters are fitted near the floor. Due to heating, air becomes hot which is lighter than cold air. So it goes up and upper air with high density comes down.
4. This cycle goes on and on and the full room becomes warm. So heaters are fitted near the floor.

4. Give scientific reasons.

Question a.
An ordinary glass bottle cracks when boiling water is poured into it, but a borosil glass bottle does not.
Answer:

1. An ordinary glass bottle cracks when we pour boiling water into it because there is a lot of temperature difference between the inner and outer parts of the glass.
2. The inner part gets hot and expands while the outer part remains cold since glass is a bad conductor of heat.
3. This unequal expansion causes the crack of glass bottle.
4. But the borosil glass bottle has a very high melting point so the temperature difference is very less, hence it doesn’t crack.

Question b.
The telephone wires which sag in summer become straight in winter.
Answer:

1. Telephone wires are made up of copper metal. Metals expand on heating.
2. In summer the copper wire expands, thus the length of the wire increases between the two poles and instead of remaining straight it sags.
3. In winter due to cold, it contracts and comes back to the original position, so it becomes straight in winter.

Question c.
Dewdrops form on the grass in winter.
Answer:

1. During the winter, the temperature of air is low, its capacity to hold the vapour is less.
2. At such times the excess water vapour is transformed into water droplets due to cold. And so the dew drops form on the grass in winter.

Question d.
In winter, why does an iron pillar feel colder than a wooden pole.
Answer:

1. Iron is a metal and metals are very good conductors of heat so it transfers heat at a much faster rate than wood.
2. That means, when we touch them, metals conducts away energy in the form of heat emitted by our hand and temperature of our hand lowers down and we get a cold’ sensation.
3. This is what makes the metal appear colder than the wood.
4. The wood is taking away heat at a much slower rate.

Project:

Question 1.
Make a note of the various examples of heat transfer seen in day-to-day life.

Class 7 Science Chapter 9 Heat Important Questions and Answers

Fill in the blanks:

Question 1.
………………… is an indicator of the heat in a substance.
Answer:
Temperature

Question 2.
………………. flows from higher temperature to lower temperature.
Answer:
Heat

Question 3.
Transfer of heat from one place to another takes place by ……………. or ……………. .
Answer:
conduction, convection, radiation

Question 4.
During conduction, particles of the substance …………….. in their place.
Answer:
vibrate

Question 5.
In a convection current, warm air travels …………….. .
Answer:
upwards

Question 6.
A …………….. is necessary for the conduction of heat.
Answer:
medium

Question 7.
The ………………. of conduction of heat through a medium depends on the medium.
Answer:
speed

Question 8.
Convection takes place only in …………… medium.
Answer:
fluid

Question 9.
Transfer of heat in the absence of a medium is called ……………… .
Answer:
radiation

Question 10.
Substances through which heat travels easily and quickly are called …………… .
Answer:
good conductors

Question 11.
Substances through which heat travels very slowly are called ………… of heat.
Answer:
bad conductors

Question 12.
Copper is a better ………… of heat than …………. .
Answer:
conductor, iron

Question 13.
………………. made first thermos flask in 1892.
Answer:
Sir James Dewar

Question 14.
Neither conduction nor convection of the heat occurs in thermos flask due to the ……………… .
Answer:
vacuum.

Match the following:

Question 1.

Column ‘A’	Column ‘B’
1. Good conductor	a. flow of particles
2. Bad conductor	b. particles vibrate
3. Conduction	c. glass
4. Convection	d. copper

Answer:

Column ‘A’	Column ‘B’
1. Good conductor	d. copper
2. Bad conductor	c. glass
3. Conduction	b. particles vibrate
4. Convection	a. flow of particles

Question 2.

Column ‘A’	Column ‘B’
1. Radiation	a. convection current
2. Black body	b. conduction
3. Vibration	c. absorbs more heat
4. A rotating paper lantern	d. no medium

Answer:

Column ‘A’	Column ‘B’
1. Radiation	d. no medium
2. Black body	c. absorbs more heat
3. Vibration	b. conduction
4. A rotating paper lantern	a. convection current

Say whether true or false, correct and rewrite the false statements:

Question 1.
Glass is a bad conductor of heat.
Answer:
True

Question 2.
In a thermos flask, hot things remain hot and cold things become warm.
Answer:
False. In a thermos flask, hot things remain hot and cold things remain cold.

Question 3.
Radiation of heat depends upon the colours of the outer surface of the body.
Answer:
True

Question 4.
During radiation, the particles of the medium vibrate.
Answer:
True

Question 5.
Copper is better conductor of heat than iron.
Answer:
True

Question 6.
During conduction, particles of the conductor leave their original place.
Answer:
False. During conduction, particles of the conductor do not leave their original place, but only vibrate in their own place.

Question 7.
Hot water is heavier than cold water.
Answer:
False – Hot water is lighter than cold water.

Question 8.
A convection current always travels down wards.
Answer:
False – A convection current always travels upwards.

Question 9.
Every warm substance continuously emits heat in all directions around itself.
Answer:
True

Question 10.
Air is a bad conductor of heat.
Answer:
True

Define the following:

1. Conduction
2. convection
3. radiation
4. Transfer of heat.

Answer:

1. Conduction: The transfer of heat from one end of a solid substance to the other, without the particles leaving their original place is called conduction.
2. Convection: Transfer of heat in fluids due to formation of currents is called convection.
3. Radiation: Transfer of heat in all directions in the absence of a medium is called radiation.
4. Transfer of heat: The flow of heat from one place to another is called transfer of heat.

Give scientific reasons:

Question 1.
Cricketers wear white clothes when playing in the sun.
Answer:
White clothes do not absorb heat but reflect back therefore cricketers wear white clothes while playing in the sun.

Question 2.
Sawdust is a bad conductor of heat.
Answer:
Sawdust is a bad conductor of heat because heat travels very slowly through it.

Question 3.
We can feel the heat of table lamp under it.
Answer:
We can feel the heat of table lamp under it because every warm substance continuously emits heat in all directions around itself by radiation.

Question 4.
Medium is necessary for conduction.
Answer:
Conduction is the transfer of heat from one end of a substance to another. Transfer of heat has to be done by particles of a substance and particles of a substance are particles of a medium. Hence, a medium is necessary for conduction.

Question 5.
Explain the structure and functioning of thermometer containers-
Answer:

1. Thermoware containers keep food hot. These containers consist two boxes fitted one inside the other.
2. The outer box is made up of plastic while the inner one is made up of a shiny metal, there is air between the two boxes.
3. Air is a bad conductor of heat. Thus, heat is not lost by either conduction or convection. Also, the shiny inner surface prevents heat loss due to radiation.
4. The container has a plastic lid. This also prevents any transfer of heat.

Question 6.
what is mailed infrared camera? Write its uses.
Answer:

1. Radiation of heat takes place from many objects in nature such as trees, mountains, stones and roads.
2. A camera has been developed which uses these radiations to make our surroundings visible even at night. This is called infrared camera.
3. It is used to keep watch on the movements of the enemy during the night.
4. It is also used to track the movements of animals in the wild.

Question 7.
Why is mercury used in a thermometer?
Answer:
Mercury is used in a thermometer because of the following properties.

1. There is a big difference between the freezing point and boiling point of mercury. Its freezing point is – 39° C and its boiling point is 357° C.
2. It is shiny and can be easily seen.
3. It does not stick to glass.
4. It expands regularly and uniformly in all conditions.

Question 8.
Write the difference between Conduction, Convection and Radiation.
Answer:

Conduction	Convection	Radiation
1. It is a mode of transfer of heat from hot part of an object to the cold part.	It is a mode of transfer of heat by means of convection currents.	It is a mode of transfer of heat in all directions without any medium.
2. It occurs in solids.	It occurs in liquids and gases.	It occurs in all objects of high temperature and vacuum.
3. It is a slow process.	It is a slow process	It is a fast process.

Question 9.
Draw and explain about the Thermos flask or Dewar flask.
Answer:

Principle:
1. As there is no medium in the vacuum between the two bottles, no transfer of heat can take place by conduction or convection.
2. Radiant heat is reflected back inside from the shiny surfaces.
3. Glass and plastic are bad conductors of heat hence they do not transfer heat either into or out of the bottle. Thus transfer of heat does not take place by any of the three modes, namely conduction, convection or radiation Hence, hot things in the flask remain hot and cold things cold.

Structure:

1. A thermos flask consists of two thin glass bottles fitted one inside the other.
2. The inner surfaces of the bottles have a silver coating to shine like a mirror.
3. A vacuum is created in the space between the two bottles by removing all the air from it.
4. A plastic or cork lid is provided to fit on the mouth of the bottle.

Draw neat labelled diagrams of:

Question 1.
The relation between density and convection
Answer:

Question 2.
Conduction of heat
Answer:

Question 3.
Convection of heat
Answer:

Question 4.
Expansion and contraction of a liquid
Answer:

Question 5.
Thermos flask
Answer:

Can you tell?

Answer the following questions:

Question 1.
Why does the halwai wrap up cloth around the end of his slotted spoon while stirring the boiling milk in his large kadhai?
Answer:
The halwai wrap up cloth around the end of his slotted spoon while stirring the boiling milk in his large kadhai because (i) His slotted spoon is made up of metal and metal is a good conductor of heat so due to constant heating spoon gets very hot which makes hand to get burnt, (ii) But cloth is a bad conductor of heat so it does not allow heat to reach till hand and halwai does not feel hot when he stirs the boiling milk.

Question 2.
Why do we hold a steel glass in a handkerchief while drinking hot milk from it?
Answer:

1. Steel is metal and it is a good conductor of heat. So due to hot milk it becomes hot and it is difficult to hold. Person’s hand get burnt due to it.
2. So it is better to hold in a handkerchief because handkerchief is made up of cloth which is a bad conductor of heat. So your hand does not feel hot.

Use your brain power!

Question 1.
Why do we wear woollen clothes in winter?
Answer:
We wear woollen clothes in winter because

1. Air is a poor conductor of heat and woollen clothes do not allow the transfer of body heat.
2. Therefore we do not feel cold in woollen clothes and get protected from cold in winter.

Question 2.
Why do we use white clothes in summer and dark or black clothes in winter?
Answer:

1. White clothes do not absorb heat, so in summer, weather is very hot and white clothes protect us from heat whereas in winter it is very cold so we need more heat.
2. Dark or black clothes absorb more heat so we get protection from cold.

Question 3.
Why is there a gap at the joints of rails and of cement concrete bridges?
Answer:

1. The joints of rails and cement concrete bridges are made of iron. Metal is a good conductor of heat so in summer due to heat it expands and its length will be increased.
2. To allow for this expansion, gaps are kept.
3. If these gaps are not kept, then after expansion the rails and cement concrete would have buckled upwards due to lack of space.
4. Due to that bridges would crack and railway tracks get crooked.

Question 4.
Why is mercury or alcohol used in a thermometer?
Answer:
Mercury is used in a thermometer because of the following properties.
Alcohol is used in a thermometer for the following properties.

1. It can measure a low temperature because its freezing point is low. (-115°C) but it can not measure higher temperature as its boiling point is low.
2. It can measure the temperature precisely because it has large expansion coefficient.
3. It’s expansion is regular.
4. Less hazardous.

Question 5.
Why hot substance does not remain as hot after two or three hours?
Answer:
A little heat is lost from around the lid and by a small amount of conduction through the vessel. So hot substance does not remain as hot after two or three hours.

Diagram based questions.

Observe the diagram and answer the given questions below it.

1.

Question a.
What is the diagram about?
Answer:
The diagram is showing us the relation between density and convection.

Question b.
Why is the ice wrapped in wire gauze?
Answer:
Ice floats on water, to make it sink, it is wrapped in wire gauze.

Question c.
What does this experiment prove?
Answer:
When a liquid is heated, its density decreases and it rises upwards. This leads to the convection currents which makes the heated liquid rise upwards and cooler liquid takes it place.

2.

Question a.
What is the diagram about?
Answer:
Expansion and contraction of a solid substance.

Question b.
Does the same thing happen in liquids and gases?
Answer:
Yes. Generally substances solids, liquids and gases expand on heating and contract on cooling.

Question c.
Give one example of this property in everyday life.
Answer:
Gaps are present in between two railway line track joints so that they do not bend due to expansion.

3.

Question a.
Label parts 1 – 4
Answer:

1. Vacuum
2. metal/plastic jar
3. Spring
4. silvered surface of the glass.

Question b.
What is the principle of this object?
Answer:
As there is no medium in the vacuum between the two bottles, no transfer of heat takes place due to conduction and convection and radiated heat is reflected back by the shiny surface.

Question c.
State the uses of the given object.
Answer:
The temperature of substances inside it are maintained for some time. Hot things remain hot and cold things cold for 2 – 3 hours.

Question d.
What is an infrared camera?
Answer:
It is a camera which uses radiations to make our surroundings visible at night. Using this camera, it is possible to keep a watch on the movements of the enemy during the night.

Question e.
What is thermoware?
Answer:
Thermoware are object which do not allow heat to escape from them. So things stay warm in them. eg. hot pot, thermos flask.

Balbharti Maharashtra State Board Class 8 Science Solutions Chapter 18 Ecosystems Notes, Textbook Exercise Important Questions and Answers.

Maharashtra State Board Class 8 Science Solutions Chapter 18 Ecosystems

Class 8 Science Chapter 18 Ecosystems Textbook Questions and Answers

1. Complete the following by using the correct option:

Question a.
Air, water, minerals, soil are ………….. factors of an ecosystem. (physical, organic, inorganic)
Answer:
Air, water, minerals, soil are physical factors of an ecosystem.

Question b.
River, ponds, ocean are …………. ecosystems, (land, aquatic, synthetic)
Answer:
River, ponds, ocean are aquatic ecosystems.

Question c.
Man is ………….. in an ecosystem. (producer, consumer, decomposer)
Answer:
Man is consumer in an ecosystem.

2. Match the following:

Question a.

Producer	Ecosystem
1. Cactus	a. Forest
2. Aquatic plants	b. Creek
3. Mangroves	c. Aquatic
4. Pine	d. Desert

Answer:

Producer	Ecosystem
1. Cactus	d. Desert
2. Aquatic plants	c. Aquatic
3. Mangroves	b. Creek
4. Pine	a. Forest

3. Give my information:

Question a.
Ecosystem.
Answer:
Ecosystem is the structure formed by the interrelationships between the living organisms and non-living components in their surrounding habitats. Living organisms are also called biotic factors while the non-living components are called abiotic factors. The abiotic and biotic factors have a reciprocal relationship with each other. The ecosystem has plants as producers, animals as consumers and microbes as decomposers.

The decomposers return the substances back to the nature by process of decomposition in which the organic complex molecules are reduced to their inorganic constituents. Thus the dead remains of plants and animals are once again recycled back to the nature in any healthy ecosystem.

Question b.
Biome.
Answer:
Biomes are a larger collection of small ecosystems which are similar in their structure. In a particular biome there are same climatic, abiotic factors and similar living organisms. Biomes are of two main types, land biomes and aquatic biomes. The land biomes exist only on land. Land biomes are of following subtypes based on the abiotic factors. E.g. Grasslands, evergreen forests, deserts, Tundra ecosystem, ecosystems in Taiga, tropical rainforests, etc. Aquatic biomes include freshwater ecosystem, marine ecosystem and brackish water ecosystem found in the creeks.

Question c.
Food web.
Answer:
The complex feeding relationships form a food web. In nature in any ecosystem, the food chains are not straight and linear. But these are quite complex. A prey is consumed by a predator but this predator can itself be a prey to some other predator. E.g. Frog is a predator for variety of insects but frog is preyed upon by snake and the snake can be eaten by a bird. The same bird can also feed on insects or frog. The interrelationships between different biotic components of any ecosystem thus form the complicated food web.

4. Give scientific reasons: 

Question a.
Plants in an ecosystem are called producers.
Answer:
are cut down causing deforestation. The wild animals lose their habitat. Many of them become extinct. There is great loss of flora and fauna due to construction of large dams. There is undue pressure on the land surface caused due to stored water column. This may cause earthquakes. The human settlements are removed as their houses and farms are immersed under water. In all the above ways large dams destroy the ecosystems.

Question b.
Large dams destroy ecosystems.
Answer:
When a large dam is constructed, the original landscape is changed. The trees are cut down causing deforestation. The wild animals lose their habitat. Many of them become extinct. There is great loss of flora and fauna due to construction of large dams. There is undue pressure on the land surface caused due to stored water column. This may cause earthquakes. The human settlements are removed as their houses and farms are immersed under water. In all the above ways large dams destroy the ecosystems.

Question c.
Rhinos were restored in Dudhwa forest.
Answer:
Long ago in last century, Dudhwa forest was the natural habitat of the one-horned Rhino. However, due to hunting and poaching, the Rhino became almost extinct. In order to restore it back the breeding in captivity was attempted and the young ones were released in the natural habitat. Saving the precious wildlife is important and hence these efforts were done.

5. Answer the following:

Question a.
What are the effects of increased population (of human beings) on ecosystems?
Answer:

1. Human population growth rate is very big as compared to other animals.
2. Moreover, they are apex consumers in an ecosystem. Just like any other organisms, ecosystems provide all the basic needs to humans, too.
3. However, man demands much more due to excessive population. The natural resources are utilized on the large scale only by man.
4. Changing lifestyles, consumerism, degradation of nature and pollution are certain aspects which are created only by human beings.
5. All these cause increased stress on the ecosystems. Large human population also produces large-scale solid wastes.

Question b.
How is urbanization responsible for destruction of ecosystems?
Answer:
When people do not get sufficient food and other amenities, they migrate to the cities. The cities provide employment for many people due to industries, factories and other facilities. Every day many people migrate to cities. This causes urbanization. Due to increased population in cities, there is more need for housing. This results in loss of agricultural lands, marshlands, wetlands, forests and grasslands, etc.

The natural ecosystems are lost in an attempt to have developmental work. Human interference causes changes in the ecosystems. When land usage is changed many naturally occurring species of plants and animals are exterminated. Animal- human conflicts are very common in newly established urban areas which are near the natural forests.

Question c.
What are the reasons for war?
Answer:
There are difference of opinions and competition over land, water, mineral resources, etc. among neighbouring countries. Moreover, there can be economic and political causes which lead to war among different countries. Many times the l religions and ethnicity are also caused for dispute. Due to international conflicts, the peace is disturbed and it results in war.

Question d.
Explain the interactions among the factors of an ecosystem.
Answer:

1. The abiotic factors such as air, water, soil, sunlight, temperature, humidity, etc. affect the biotic factors, i.e. the surviving plants, animals and microbes in the ecosystem.
2. The type of abiotic factors in an ecosystem determine the survival of biotic factors. The population of these biotic factors is also dependent on the quality of abiotic factors.
3. The proportion of abiotic factors in an ecosystem fluctuates as biotic factors use up or release particular abiotic factors.
4. Every biotic factor also interacts with its necessary abiotic factors as well as other biotic factors around it.

Question e.
Differentiate between evergreen forests and grasslands.
Answer:

Evergreen forests	Grasslands
1. About seven percent of the Earth’s surface is occupied by evergreen forests.	1. About 30 percent of the Earth’s surface is covered by grasslands.
2.  More than half of the earth’s terrestrial plants and animals are seen in evergreen forests.	2. Grazing animals are seen in grasslands.
3. Tropical evergreen forests are dense, multi-layered.	3. Grasslands consist of tall grass. There are wild grasses and there may be some trees.
4. These forests are found in the areas receiving more than 200 cm annual rainfall i.e. very heavy rainfall.	4. There is an average of 20 – 35 inches of rainfall a year in grasslands.
5. Tropical regions show evergreen forests.	5. Several parts of the world have grasslands.

6. Describe the following pictures:

Question a.
Describe the following pictures

Answer:
The picture no. 1 is showing desert ecosystem, while the picture no. 2 is showing a forest ecosystem where a wetland (a lake) is also shown. In desert ecosystem, the producers are green cactus and a palm tree. Since in desert there are scanty rains, the vegetation is very less. The soil is sandy soil. The consumers of the desert are also limited.

In the above picture camel is shown which is a primary consumer in the desert ecosystem. Camel is very well adapted for desert life. There is also the scarcity of water in desert and hence cactus shows xerophytic (suitable to survive in desert) adaptations.

In second picture, the forest ecosystem is shown because we can see elephant and tiger in the picture. Also, giant hornbill is sitting on the tree. This forest must be tropical evergreen forest. The rainfall is heavy in such areas and hence different types of wetlands can be seen in forests. Wetlands support variety of life. A separate aquatic ecosystem does exist here which is closely interconnected with the terrestrial ecosystems through food chains and food web.

The birds utilize the fish as their prey. The wild animals come to wetlands to quench their thirst. In this picture the plants, grass, etc. are producers, small fishes in the lake are primary consumers. They will be eaten by larger fishes which are secondary consumer in the aquatic ecosystem. The elephant is herbivorous animal and hence it is primary consumer. Snake is the secondary consumer while the birds of prey (eagle that is flying) and tiger are tertiary consumers.

Can you recall?

Question 1.
Which factors do you find in your surroundings?
Answer:
In our surroundings there are abiotic and biotic factors. The biotic factors are animals and plants in the surroundings. The invisible bacteria and fungi also have important role in the ecosystem as decomposers. Important abiotic factors are air, water, land, sunlight, etc.

Question 2.
Are these factors directly or indirectly related to you?
Answer:
We are directly or indirectly connected to every single factor in the surrounding in which we reside. For the requirement of food, we are dependent on plants and animals. For our survival we continuously need oxygen, water and other minerals, etc.

Classify:

Question 1.
Classify the following into living and non-living factors. Sunlight, Sunflower, Elephant, Lotus, Algae, Stone, Grass, Water, Ant, Soil, Cat, Fern, Air, Lion.
Answer:

Living Factors	Non-living Factors
Sunflower, Elephant, Lotus, Algae, Grass, Ant, Cat, Fern, Air, Lion.	Sunlight, Stone, Water, Soil, Air.

Can you tell?

Question 1.
What is the role of microbes in above interaction?
Answer:
Microbes play the role of decomposers in the above interactions.

Question 2.
How do producers obtain abiotic factors?
Answer:
Producers obtain solar energy from sunlight. The other nutrients are obtained from soil, water and air.

Question 3.
From where do the consumers get their food?
Answer:
Consumers get their food from producers and other consumers.

Project:

Question 1.
Visit an ecosystem nearby, List the biotic and abiotic factors in it. Show with pictures or sketches, how they are dependant on each other.

Question 2.
With the help of internet find out the loss of ecosystems due to wars or atomic explosions. Describe in your words.

Class 8 Science Chapter 18 Ecosystems Important Questions and Answers

Complete the following by using the correct option:

Question 1.
Biotic community is another name for ………. (ecology, ecosystem, population)
Answer:
Biotic community is another name Biotic for ecosystem.

Question 2.
Microbes in an ecosystem are ………… (producers, consumers, decomposers)
Answer:
Microbes in an ecosystem are decomposers.

Question 3.
Many types of ecosystems are found in ………… (oceans, deserts, biosphere)
Answer:
Many types of ecosystems are found in biosphere.

Question 4.
………….. is a type of grassland ecosystem. (Taiga, Tundra, Desert)
Answer:
Taiga is a type of grassland ecosystem.

Question 5.
Gir forest in Gujarat is the only habitat/shelter for the spectacular ………….. (Asiatic lion, Royal Bengal tiger, One-horned rhino)
Answer:
Gir forest in Gujarat is the only habitat shelter for the spectacular Asiatic lion.

Correct the following statements by changing one or two words:

Question 1.
Primary, secondary, tertiary consumers are the abiotic factors of the ecosystem.
Answer:
Primary, secondary, tertiary consumers are the biotic factors of the ecosystem.

Question 2.
Most of the ecosystems are simple.
Answer:
Most of the ecosystems are complex.

Question 3.
The word ecosystem was brought in the use by Ray Claffam.
Answer:
The word ecosystem was brought in the use by A.G. Tansle.

Question 4.
Specific ecosystem developed in a vast area is called a biosphere.
Answer:
Specific ecosystem developed in a vast area is called a biomes.

Question 5.
Longer summer and limited rain develop very tall plants in the grassland ecosystem.
Answer:
Longer summer and limited rain develop dwarf plants in the grassland ecosystem.

Question 6.
29 % of the earth surface is covered by water and only 71 % has land on it.
Answer:
71 % of the earth surface is covered by water and only 29 % has land on it.

Question 7.
Dams increase the water current in lower area.
Answer:
Dams lessen the water current in lower area.

Match the following:

Question 1.

Column ‘A’	Column ‘B’
1. The Great Himalayan National Park	a. Asiatic lion
2. Kaziranga	b. Tigers
3. Bharatpur	c. Aquatic birds
4. Ranthambore	d. One-horned Rhino
5. Gir forest	e. White panther

Answer:

Column ‘A’	Column ‘B’
1. The Great Himalayan National Park	e. White panther
2. Kaziranga	d. One-horned Rhino
3. Bharatpur	c. Aquatic birds
4. Ranthambore	b. Tigers
5. Gir forest	a. Asiatic lion

Find the odd one out:

Question 1.
Typha, Pistia, Eichhornia, Dipterocarpus
Answer:
Dipterocarpus. (All others are aquatic plants.)

Question 2.
Teak, Parthenium, Pine, Sandalwood
Answer:
Parthenium. (All others are forest trees.)

Question 3.
Giraffe, Zebra, Cheetah, Elephant
Answer:
Cheetah.. (All others are surviving grassland animals, Cheetah is a forest animal that is extinct from Asia.)

Question 4.
Hyena, Cow, Deer, Rabbit
Answer:
Hyena. (All others are primary consumers, Hyena is tertiary consumer.)

Question 5.
Fusarium, Leptocorsia, Aspergillus, Polycarpus
Answer:
Leptocorsia. (All others are decomposers, Leptocorsia is primary consumer.)

Taking into consideration the relationship in the first pair, complete the second pair :

Question 1.
Plants : Producers : : ……… : Consumers
Answer:
Animals

Question 2.
Secondary consumers : Jackals : : Tertiary consumer : ………..
Answer:
Kite/Lion/Hyena

Question 3.
Goat, sheep : Grassland ecosystem : : Tigers : …………..
Answer:
Forest ecosystem

Question 4.
Desert : Land biome : : Creek : …………….
Answer:
Aquatic biome

Question 5.
Limited rain : Grassland ecosystem : : ……….. : Tropical rainforests
Answer:
Excessive rain.

Answer in one sentence:

Question 1.
What is an ecosystem?
Answer:
The structure which is formed due to interactions between abiotic and biotic factors is called an ecosystem.

Question 2.
What is an ecological niche?
Answer:
The position of any living organism with reference to other living organisms and the role played by that organism is called ecological niche.

Question 3.
How are types of ecosystems formed?
Answer:
Types of ecosystems are formed according to size, place, climate, types of plants and animals that survive in that ecosystem.

Question 4.
Give examples of land biomes.
Answer:
Grasslands, evergreen forests, deserts, Tundra or polar ecosystem, ecosystems in Taiga, tropical rainforests, etc. are land biomes.

Question 5.
What are the reasons for tourism among the people?
Answer:
Tourism is mainly because people like to visit scenic places, undertake nature watch, wish to visit to sacred places and for entertainment purpose.

Question 6.
Why we should protect natural ecosystems?
Answer:
Natural ecosystems must be protected as they maintain balance in the biosphere.

Give my information Write short notes:

Question 1.
Dudhwa forest.
Answer:
Dudhwa forest is in Uttar Pradesh. About a century back, Dudhwa forest was the habitat for one-horned Rhino. However, due to hunting and poaching in 20th century, this animal became endangered. Thus to restore their populations, on 1st April 1984 rhino were introduced there again. Rhinos can were bred in captivity followed by releasing them back into natural ecosystem.

For this purpose at first the land was selected. This was 27 square km grassland and forest with continuous water supply through natural resources. Two observatories were established for making these efforts successful. Now Dudhwa is known for one¬horned Rhino population.

Question 2.
Aquatic ecosystems.
Answer:
Earth’s 71 % of surface is covered over by aquatic ecosystems. They are of three main types, viz. fresh water ecosystem, marine ecosystem and brackish water ecosystem. Rivers, lakes and ponds and streams are some of the fresh water ecosystem. Fresh water contains less salt and hence it is potable. Marine water has more salinity, i.e. its salt content is high. Brackish water ecosystem is present in the creeks. Here the saline and fresh water mix together. Hence salinity here is lesser than that of the marine water.

Give scientific reasons:

Question 1.
Microbes are called decomposers.
Answer:
Decomposition is the process in which the organic compounds are broken down to their inorganic constituents. The organic substances such as carbohydrates, proteins and lipids which are locked in the dead remains of plants and animals are converted into hydrogen, oxygen, calcium, iron, sodium, potassium, etc. by microbes. Therefore, microbes are called decomposers.

Use your brain power:

Question 1.
Which biotic factors get affected due to a dam?
Answer:
The biotic factors include plants, animals and humans. Lot of vegetation is submerged from the place where dam is constructed. The forests are wiped out. Large scale deforestation takes place in the proposed dam area. Wildlife is destroyed completely. The resident animals whose habitat are there either migrate away or are killed due to lack of their food and shelter. Many instances of animal-human conflicts arise when the wild animals drift to the neighbouring human settlements.

If human settlements are shifted, people are displaced. They lose their houses and agricultural land. Though compensation is given to them, there is great change for the people. Water current in lower area of the dam is reduced due to construction of dam-walls. Therefore, the original lotic (running 5 water) ecosystems that were present are destroyed after the construction of dam.

Question 2.
What will be the effects on biotic factors in the running water of river?
Answer:
The aquatic flora (plants) and fauna (animals) are well adapted to their habitats. The running water ecosystems are known as lotic ecosystems. The non-moving waters on the contrary create lentic ecosystems. Lotic ecosystems provide special adaptations to the plants and animals living therein. Plants are mostly in the form of freely floating algae and phytoplankton. Animals are well adapted for swimming in the currents of water. The fishes especially show a stream-lined body, fins for swimming, and gills to take up dissolved oxygen in the water. The other animals are also well adapted to the currents of water.

Think about it:

Question 1.
Can we call a tree an independent ecosystem?
Answer:
The huge tree can be an independent ecosystem. On one such tree there may be different habitats. Variety of insects thrive on huge tree by making their habitats in cracks and crevices on the tree. Many birds visit the tree to feed on such insects. There are many bird species that live in the hollow of the tree. Garden lizards, chameleons, snakes are the different reptiles seen associated with the tree ecosystem.

Squirrels, rabbits, bats are the mammals which take shelter in and around the trees, also inhabit a tree variety of fungi, lichens, mosses and epiphytic plants like orchids survive on the huge trees. Many food chains and complicated food webs are formed with the support of the tree. Thus one can say that a tree is an independent ecosystem.

Question 2.
Today Divija visited a hill. Honey: bees were hovering on flowers. One of them stung Divijia’s hand. Divija was hurt due to that sting and said with anger that all the honey-bees from the whole world must get destroyed. Afterwards, she thought what will happen if all honey-bees are destroyed? We will get honey, nothing more. What would be your explanation to Divija?
Answer:
Honey bees provide us with honey and bee-wax. Both of these are commercial products. But more than that the role played by honey bees in the pollination of flowers is very important. Due to their nectar collecting behaviour, they bring about pollination of the flowers.

Presence of honey bees is thus very essential for the agriculture and horticulture. Without honey bees, the growth of fruits and grains will not be possible, if pollination and subsequent fertilization does not take place in nature. This will create famine-like conditions. Therefore, honey bees’ position in the nature is very important.

Chart based questions:

Question 1.
Complete the following chart in context to a grassland.

Answer:

Question 2.
Write the information about various components of forest.

Answer:

Question 3.
Observe such ecosystems around you and complete the following chart.

Answer:

Question 4.
Complete the table.

Answer:

National Park/Sanctuary	State
1. Gir	Gujarat
2. Dachigam	Jammu-Kashmir
3. Ranthambore	Rajasthan
4. Dajipur	Maharashtra
5. Kaziranga	Assam
6. Sunderbans	Bengal
7. Melghat	Maharashtra
8. Periyar	Kerala

Question 5.
Complete the following chart:

Answer:

Diagram based questions:

Question 1.
Correct the following diagram:

Answer:

MCQs based on experiment:

Question 1.
Which one out of the following is not biotic factor?
(a) Humidity
(b) Rabbit
(c) Snake
(d) Bacteria
Answer:
(a) Humidity

Question 2.
Which climatic factor is causing migration of the birds in certain regions of the earth?
(a) Humidity and rainfall
(b) Ambient temperature
(c) Amount of carbon dioxide
(d) Amount of plant matter
Answer:
(b) Ambient temperature

Question 3.
Which abiotic factor mainly distinguishes marine water from the fresh water?
(a) Temperature
(b) Dissolved oxygen:
(c) Salinity
(d) Surface tension
Answer:
(c) Salinity

Question 4.
Why is creek water different from the river water?
(a) Creek water is more polluted than the river water.
(b) Creek water is less salty than the river water.
(c) Creek water is more saline than the river water.
(d) Creek water is less turbulent than the river water.
Answer:
(b) Creek water is less salty than the river water.

Question 5.
Which land biome shows presence of cacti plants more?
(a) Polar regions
(b) Grasslands
(c) Rainforest
(d) Desert
Answer:
(d) Desert

Projects:

Collect information

Question 1.
What are the possible threats to grasslands?
Answer:
Man tries to use grasslands for agricultural purpose. This transformation causes loss of natural ecosystem. Many animals from grasslands are killed by hunting and poaching. Though now Wildlife Act has protected these animals, many wildlife species are already extinct. There are chances of forest fires which is the greatest threat to grasslands. The global warming may also cause grasslands to become a desert.

Question 2.
Why did Asian Cheetah become extinct in last century?
Answer:
When British ruled India, Asian Cheetah was hunted to a great extent. The kings and British rulers did rampant hunting. The forest lands were also reduced due to encroachment by humans to build their settlements. Dams were constructed. Mega highways, bridges and roads caused loss of habitat for Asian Cheetah. Cheetah needs large thickly forested territory. This was lost due to all man-made activities. All these reasons made Asian Cheetah extinct in last century.

Question 3.
Observe Asian Cheetah on internet. Describe it.
Answer:
Cheetah is the fastest running feline animal on the earth. Though from Asian regions it is said to be extinct, in African grasslands, its occurrence is still there. But it is endangered animal. By 2016, the global cheetah population is estimated at approximately 7,100 individuals in the wild. Several African countries have taken steps to improve cheetah conservation measures.

Cheetah has a slender body, deep chest, spotted coat. Its head is small rounded and on the face there is black tear-like streaks. It has long thin legs and a long spotted tail. Cheetah in India were tamed during Moghul period for assisting in hunting. Stories about such episodes are commonly told. However, the last Cheetah in India was spotted in Bastar, M.P. in 1948.

Balbharti Maharashtra State Board Class 7 Geography Solutions Chapter 7 Soils Notes, Textbook Exercise Important Questions and Answers.

Maharashtra State Board Class 7 Geography Solutions Chapter 7 Soils

Class 7 Geography Chapter 7 Soils Textbook Questions and Answers

1. Complete the following table.

Factor/Process	Role in the formation of soil
(1) Parent rock	…………….
(2) Regional climate	……………
(3) Organic material	…………..
(4) Micro­organisms	……………..

Answer:

Factor/Process	Role in the formation of soil
(1) Parent rock	The rock gets weathered depending on the hardness of the rock and the climate of the region. It turns into powdery material which further turns into soil.
(2) Regional climate	When the rock is exposed to a different climates, the same type of rock gives rise to different types of soil.
(3) Organic material	The organic material gets mixed into weathered powdery material and turn it into soil.
(4) Micro­organisms	Microorganisms help in decomposing the dead remains of organic materials and get mixed into the soil to form humus.

2. Why do the following occur?

Question 1.
To the west of Sahyadris, laterite soils are formed from the basalt rock.
Answer:

• Laterite soils are formed in regions of heavy rainfall.
• The climate of western Sahyadris is hot & humid.
• This leads to leaching of basalt rocks due to which there is formation of laterite soils.

Question 2.
Humus content in the soil increases.
Answer:

• Microorganisms and certain other organism help in decomposing the dead remains of organic materials.
• The biotic material thus produced is called humus.
• If organic manures, vermicompost compost are used regularly, the humus content in the soil increases.

Question 3.
Soil formation process is faster in the equatorial climate.
Answer:

• In the region of high rainfall and higher temperature the process of soil formation is faster.
• Equatorial climatic region have high temperature and receive high rainfall.
• Thus soil formation process is faster in the equatorial region.

Question 4.
The salinity of the soil increases.
Answer:

• Due to excessive irrigation, the salts from the soil are drawn upwards.
• This increases the salinity of the soil.

Question 5.
Rice is the staple diet of the people from Konkan.
Answer:

• Hot & humid climate, heavy rainfall & fertile alluvial soil are favourable for rice cultivation.
• This soil has good water holding capacity. Since these conditions are found in the konkan region, rice is grown on a large scale here.
• So rice is the staple diet of the people from Konkan.

3. Give information on:

Question 1.
Measures of soil conservation
Answer:
The following are the measures of soil conservation:

(i) Afforestation / Planting trees: Planting trees can control the velocity of wind. This helps reducing erosion by wind. The plant roots hold the soil and also reduces the erosion of soil.

(ii) Continuous contour trenches: Construction of continuous contour trenches at different height checks the velocity of water running along the slopes & hence reduces soil erosion. The water arrested in these trenches percolates into the ground.

(iii) Implementation of watershed Development program: The Government of Maharashtra has implemented the watershed development programme under which constructing embankment along slopes in rural areas, introducing CCTs along steep slopes etc. are undertaken. This led to the success of the scheme ‘Arrest water, let it percolate’. This has resulted in raising the ground water levels & reducing the erosion of soil.

(iv) Implementation of Jalayukt Shivar: Under the scheme of Jalayukt Shivar, works like construction of farm bunds, arresting waters of small streams, connecting the streams etc. are being carried out on a large scale.

Question 2.
Organic Manures.
Answer:
(i) Organic manures in farming, helps to maintain the pH balance.
(ii) It also increases the proportion of humus, and retain the fertility of soil.

Question 3.
Place where you will get the information about the suitability of a soil for a particular crop.
Answer:
(i) The information about the suitability of a soil can be obtained from Department of Agriculture of Government of Maharashtra, Natural Resource conservation services, soil testing laboratories in various states and at many agricultural universities.

(ii) The type of soil, soil fertility, pH status of the soil, etc. are determined in soil testing.

(iii) Based on the testing, an analysis of the soil is done & information about the suitability of a soil for a particular crop is provided.

Question 4.
Importance of soils for plant growth.
Answer:
(i) Soil is important for plant as it hold roots that provide support for plants and stores nutrient for the growth of plants.
(ii) Fertile soils favour plant growth.

4. Complete the following table with reference to soil.

Action	Effect	Result (W.R.T. fertility)
Construction of embankments.
	Wind speed decreased.
Farm land is kept fallow for some period.	Helps to maintain the pH balance and increase the proportion of humus.	Increases the fertility of soil.
Regular use of organic manures, vermicompost and compost.
	Check the velocity of water running along the slopes.
Litter is burnt in the farm.
Decomposed vegetal litters, roots of plants and remains of animals.
	Salt content in the soil increases.
	Leads to the lowering of humus content in the soil.

Answer:

Action	Effect	Result (W.R.T. fertility)
Construction of embankments.	Protects soil from being washed away.	Protects fertility of soil.
Planting trees.	Wind speed decreased.	Protects fertility of soil
Farm land is kept fallow for some period.	Helps to maintain the pH balance and increase the proportion of humus.	Increases the fertility of soil.
Regular use of organic manures, vermicompost[1] and compost.	Humus content increased.	Increases the fertility of soil.
Trenches are dug across a slope.	Check the velocity of water running along the slopes.	Protects fertility of soil
Litter is burnt in the farm.	Decreases the amount of organic material in soil.	Decreases the fertility of soil.
Decomposed vegetal litters, roots of plants and remains of animals.	Proves favourable for micro organism.	Increases the fertility of soil.
Excessive Irrigation	Salt content in the soil increases.	Decreases the fertility of soil
Chemical fertilizers used excessively.	Leads to the lowering of humus content in the soil.	Decreases the fertility of soil

Activity:

1. Visit a soil testing centre/laboratory and note the work that is carried out in the centre.
2. Prepare compost at home or in your housing society.
3. Visit a place where ‘Arrest water, let it percolate’ is being implemented. Collect information about it and make a note of it.

Class 7 Geography Chapter 7 Soils InText Questions and Answers

Think about it:

Question 1.
Rohit and Prateeksha noted that their field had yielded a bumper crop. But they also noted that a part of their field had a stunted growth of plants. What investigation will you suggest to them?
Answer:
I would suggest that they should check whether organic manures, are used evenly on all the parts of the field. Also, they should check whether that part of the field is getting adequate supply of water or not.

Question 2.
Why do equatorial regions have fertile soils?
Answer:
The sun rays are perpendicular in equatorial
regions so the climate is very hot and humid. This region also receives very heavy rainfall. As the process of soil formation is faster in these regions, equatorial regions have fertile soil. Also vegetal litter roots of plants, remains of animals, etc.; get decomposed adding to soil fertility.

Question 3.
Why is the vegetation sparse in deserts?
Answer:
A desert is a barren area of land where a little precipitation occurs and consequently living conditions for plant and animal life are very hostile. It is an area where the soils are not fertile & hence vegetation is scanty.

Try this:

• Take three flower pots of the same size.
• Keep one pot empty. Fill the second pot. With water after closing the hole at the bottom and fill the third pot with soil.
• Put a few seeds in all of them. (You may use aserio, peas, gram, fenugreek, wheat, green gram, coriander seeds, etc.)
• Keep all the three pots in the sun. and water the empty pot and the soil-filled pot for 4-5 days. Observe and answer the following.

Question 1.
What happened to the seeds put in the empty pot and pot filled with water?
Answer:
Seeds in the empty pot and the pot filled with water did not germinate and did not show any sign of growth.

Question 2.
What happened to the seeds put in the pot (c) filled with soil?
Answer:
Seeds germinated and we could see some small twigs branching out.

Question 3.
What do you learn from this?
Answer:
We learn that plants need sunlight, water and soil to grow.

Class 7 Geography Chapter 7 Soils Additional Important Questions and Answers

Fill in the blanks:

Question 1.
_____ rock in a region is an important factor in soil. (Parent, Basalt, Granite)
Answer:
Parent

Question 2.
The process of weathering depends on the _____ of the region. (climate, weather, soil)
Answer:
climate

Question 3.
The _____ rock of the Deccan Plateau in Maharashtra turns into black soil after weathering. (granite, basalt, parent)
Answer:
basalt

Question 4.
______ soils along the river beds give higher yields. (Infertile, Fertile, Coarse)
Answer:
Fertile

Question 5.
The _____ material comes from the decomposition of the remains of the plants and animals in that region. (biotic1, abiotic, pH)
Answer:
biotic1

Question 6.
______ is a complete ecosystem.(Soil, Humus, weathered rocks)
Answer:
Soil

Question 7.
Food crops like jowar and bajra are produced in the _____ soils of Maharashtra Plateau. (regur, coarse, laterite)
Answer:
regur

Question 8.
The local agriculture produce determines the _______ diet of the people. (staple, supplementary, secondary)
Answer:
staple

Question 9.
The proportion of humus is negligible in _____ soil. (coarse, black, laterite)
Answer:
coarse

Question 10.
Planting trees can also control the _____ of the wind. (velocity, direction, temperature)
Answer:
velocity

Question 11.
Rocks like granite or gneiss in South India give rise to ____ soil. (black, red, regur)
Answer:
red

Question 12.
In the humid climate of western Sahyadris the leaching of basalt rocks leads to formation of ___ soil. (black, lateritic, red)
Answer:
lateritic

Question 13.
The excessive spraying of chemicals and use of chemical fertilizers lead to ______; (soil degradation soil fertility, soil powder)
Answer:
soil degradation

Complete the following sentences:

Question 1.
The biotic material comes from _____.
Answer:
the decomposition of the remains of the plants and animals in that region

Question 2
Microorganisms ajnd certain other organisms help decompose the dead remains of ______.
Answer:
organic materials

Question 3.
Production of compost needs sufficient period of time and ______.
Answer:
elements like organic waste, water, heat, etc.

Question 4.
In the region of high rainfall and higher temperatures, _____.
Answer:
the process of soil formation is faster

Question 5.
In regions of low temperatures and low rainfall the _____.
Answer:
soil formation takes more time

Question 6.
High use of chemical fertilizers, insecticides _____.
Answer:
leads to the degradation of soils

Question 7.
In the areas where the soil is not fertile, _______.
Answer:
egetation is scanty

Question 8.
When man realized that sowing of seeds in the soil leads to the growth of plants and yields crops, ______.
Answer:
he started using soil as a resource

Question 9.
Excessive irrigation draws the salts from the soil upwards and ______.
Answer:
makes the soil saline and then unproductive

Question 10.
Keeping the farmland fallow for some period and cultivating different crops alternatively is important ________.
Answer:
to help retain the fertility of soils.

Give one word for the following:

Question 1.
Soil formed due to weathering of basalt rock.
Answer:
Black soil

Question 2
Soil formed due to the leaching of the basalt rock.
Answer:
Lateritic soil

Question 3.
Biotic material mixed into the soils.
Answer:
Humus

Question 4.
The excessive spraying of chemicals and use of chemical fertilizers.
Answer:
Soil degradation

Question 5.
The govt, scheme, work like construction of farm bunds, arresting waters of small streams, etc.
Answer:
Jalayukt Shivar.

Who am I?

Question 1.
I am a very important rock factor in soil formation.
Answer:
Parent rock

Question 2
I form due to weathering of basalt rock. Jowar and Bajra mostly grow on this soil.
Answer:
Regur soil / Black soil

Question 3.
I am found in the hilltops of the western part of the Deccan plateau.
Answer:
Coarse soil

Question 4.
I am black in colour and have less organic components.
Answer:
Regur or Black soil

Question 5.
I am orange in colour and mostly found in the coastal belt of Konkan.
Laterite soil

Question 6.
I am found at the mouth of the river in the western coastal strip.
Answer:
Alluvial soil of the coastal strip

Question 7.
I am mainly found in areas of extreme rainfall but not very useful for agriculture.
Answer:
Yellow brown soil

Question 8.
I am a method of soil conservation which controls the velocity of wind.
Answer:
Afforestation / planting trees

Match the columns:

Question 1.

Column I	Column II
(1) Coarse soil	(a) Alluvium deposition
(2) Regur soil	(b) Eastern part of Bhandara
(3) Laterite soil	(c) Ajanta, Balaghat, Mahaden hills
(4) Alluvial soil	(d) Coastal belt of konkan
(5) Yellow-brown soil	(e) Weathering of basalt rock

Answer:
1 – c
2 – e
3 – d
4 – a
5 – b

Answer the following questions in short:

Question 1.
What do you mean by ‘Soil’?
Answer:
(i) The uppermost layer of the earth’s crust is called ‘Soil’.
(ii) It contains the organic as well as mineral matter necessary for the growth of plants.

Question 2
What are the factors necessary for the soil formation?
Answer:
Soil is formed by:

• Weathering of the parent rock material.
• Climatic conditions of the region.
• The decomposition of plant remains.
• Animal manures and dead animals.
• Very long period of time.

Question 3.
What is leaching ?
Answer:
(i) Leaching is a process is which the salts & other soluble material are washed out of the rock through percolation of water.
(ii) This process is dominant in the areas of high rainfall & humid climate.

Question 4.
What is Humus?
Answer:
(i) The decaying of organic material such as dead leaves, stems, root of the plant, vegetal litters, decomposed remains of animals get mixed into the soil.
(ii) This results in the formation of “Humus” thus retaining the fertility of soil.
(iii) If the proportion of humus in the soil is greater, the soil becomes fertile.

Question 5.
What leads to the degradation of soils?
Answer:
(i) For getting higher production, different types of chemical fertilizers, insecticides are used profusely.
(ii) This leads to the degradation of soils.

Question 6.
What led to record agricultural production?
Ans,
(i) To get richer harvests man made efforts to increase the fertility of soils.
(ii) In the process, use of different fertilizers became a practice which led to record agricultural production.

Question 7.
What is soil erosion?
Answer:
(i) When a layer of soil (top layer of soil) get removed due to wind or water it is called soil erosion.
(ii) Running water, climate and diversity in physiography are the reasons of soil erosion.

Question 8.
What helps to maintain the pH balance of the soil?
Answer:
(i) Organic manures, vermicompost, compost are used regularly.
(ii) It helps in maintaining the pH balance and retaining the fertility of the soil.

Why do the following occur:

Question 1.
Rice is the staple diet of the people from Konkan.
Answer:
(i) Hot & humid climate, heavy rainfall & fertile alluvial soil are favourable for rice cultivation.
(ii) This soil has good water holding capacity. Since these conditions are found in the konkan region, rice is grown on a large scale here.
(iii) So rice is the staple diet of the people from Konkan.

Question 2.
Soil Erosion.
(i) A layer of soil gets removed due to wind or water.
(ii) Running water, climate and diversity in physiography are the reasons of soil erosion.

Question 3.
Soil degradation.
Answer:
(i) To obtain a higher agricultural yield, chemical fertilizers, insecticides, weedicides, etc. are used.
(ii) The excessive spraying of chemicals and use of chemical fertilizers leads to soil degradation.

Give geographical reasons:

Question 1.
Planting trees is necessary to conserve the soil.
Answer:
(i) A layer of soil gets removed due to wind or water which leads to soil erosion.
(ii) Planting trees controls the velocity of the wind, thus reducing the erosion of soil by wind.
(iii) The roots of the plants hold the soil which also prevents soil erosion.

Question 2
Continuous contour trenches are constructed along the slopes.
Answer:
(i) Construction of continuous contour trenches (CCTs) at different heights checks the velocity of water running along the slopes.
(ii) This reduces soil erosion.

Question 3.
It is advisable to use organic manures, vermicompost and compost regularly.
Answer:
(i) Use of organic manures, vermicompost, compost helps maintain the pH balance.
(ii) It also increases the proportion of humus thus retaining the fertility of soil.
(iii) Hence, it is advisable to use organic manures, vermicompost & compost regularly.

Question 4.
There emerged competition among the people to discover fertile lands and settle there.
Answer:
(i) Man started producing greater amount of food crops for the growing population.
(ii) He realized that crop production and prosperity in agriculture depends on the fertility of soil and the optimum availability of water.
Hence, there emerged competition among the people to discover fertile lands & settle there.

Question 5.
There was a rise of Indus civilization.
Answer:
(i) When man realized that the fertile soils along the river beds give higher yields.
(ii) He settled in the valleys and started living there in groups.
(iii) This led to the rise of Indus civilization.

Question 6.
Countries like Saudi Arabia, Qatar, Oman, etc., fulfil their requirements by importing food from other countries.
Answer:
(i) In countries like Saudi Arabia, Qatar, Oman etc. the soils are not arable so there is need to fulfil their food requirement.
(ii) Hence, countries like Saudi Arabia, Qatar, Oman import food from other countries.

Question 7.
Lets find the names of the soils we have learnt and which regions they are found?
Answer:

Soils	Answers	Regions
(1) RUGER	Regur	(a) Western part of Deccan Plateau and eastern part of Vidarbha.
(2) LUILALVA	Alluvial	(b) Panvel, Uran Coast, Dharamtar creek.
(3) OARCSE	Coarse	(c) Ajanta, Balaghat and Mahadeo hills.
(4) AEILTRITE	Laterite	(d) Coastal belt of Konkan, West of Sahyadris and East of Vidarbha.

Make Friends with maps!
Observe the map given below and answer the following questions:

Question 1.
Which soil occupies most of the areas in Maharashtra?
Answer:
Black (Regur) soil occupies most of the areas in Maharashtra.

Question 2
In which areas are laterite soils found?
Answer:
Laterite soil is found in Raigad, Ratnagiri,Sindhudurg and some parts of Gadchiroli and Nashik.

Question 3.
Which soil is found in parts of the Sahyadri ranges?
Answer:
Yellow Brown soil is found in parts of the Sahyadri ranges.

Question 4.
In which region is alluvial soil found?
Answer:
Alluvial soil is found in Mumbai Suburban District, Mumbai city district some parts of Thane & Palghar district.

Question 5.
Which soil is found in the river valleys of Maharashtra?
Answer:
Fertile Alluvial Soil is found in the river valleys of Maharashtra.

Balbharti Maharashtra State Board Class 6 History Solutions Chapter 11 Ancient India and the World Notes, Textbook Exercise Important Questions and Answers.

Maharashtra Board Class 6 History Solutions Chapter 11 Ancient India and the World

Class 6 History Chapter 11 Ancient India and the World Textbook Questions and Answers

1. Name the following:

Question 1.
Places where articles made in Rome were found.
Answer:
Kolhapur and Arikamedu in Tamil Nadu.

Question 2.
A new style of art emerged during the Kushana period in India.
Answer:
Gandhara style of art.

Question 3.
The language of the books Mahavansa and Deepvansa.
Answer:
Pali language.

Question 4.
A country to which Buddhism had spread in the ancient period.
Answer:
Sri Lanka.

2. Think and expand/elaborate:

Question 1.
Indian culture had an impact on southeast Asia.
Answer:

• Indian culture had a deep impact on the art and cultural life of southeast Asia.
• Dance-dramas based on stories from Ramayana and Mahabharata are popular in Indonesia even today.
• In later years, temples of Lord Shiva and Vishnu were also built there.

Question 2.
The spread of Buddhism in China became easier.
Answer:

• In the first century CE, the Ming emperor of China invited the Buddhist bhikkhus Dharmarakshaka and Kashyapmatanga to China.
• The Bhikkhus translated many Indian Buddhist texts into Chinese language.
• This made the spread of Buddhism in China easier.

3. What would you do if you are encouraged in your favourite hobby ?
Answer:
If someone encouraged me, it will make me very happy and boost my self-confidence. Thus I will further expand my horizon by gaining more knowledge and enhancing my hobby.

4. Describe a picture:

A picture of the Gandhara style sculpture on a stupa in Hadda, Afghanistan is given in this chapter. Observe it and write about it.

5. Find out more about:

Question 1.
The Gandhara style of art.
Answer:
Under the influence of the Greek art of sculpture, a new form of art emerged in India during the Kushana period. It is called Gandhara school of art. In the Gandhara, art school images of Gautam Buddha were mainly carved in Gandhara.

Question 2.
The Silk Route.
Answer:
Chinese silk was in great demand in India. Merchants in ancient India supplied Chinese silk to western countries. The land route by which the silk trade was carried on was called the silk route. Some ancient places in India were connected to this route. The Chinese Buddhist Bhikkhus also came to India through this silk route.

6. Mark the countries of Southeast Asia mentioned in the chapter on an outline map.

Activity:

Obtain information about a form of art of your choice and present it in your class.

Class 6 History Chapter 11 Ancient India and the World Additional Important Questions and Answers

Complete the sentence by choosing the correct option:

Question 1.
People of the Harappan civilisation had developed trade relations with the countries of the ______.
(a) north
(b) west
(c) south
Answer:
(b) west

Question 2.
________ had spread to Afghanistan and to many countries of Central Asia.
(a) Zoroastrianism
(b) Jainism
(c) Buddhism
Answer:
(c) Buddhism

Question 3.
The writings of the Greek historians introduced India to the ______ world.
(a) western
(b) eastern
(c) central
Answer:
(a) western

Question 4.
Under the influence of the Greek art of sculpture, a new form of art emerged in India during the ____ period.
(a) Gupta
(b) Kushana
(c) Vakataka
Answer:
(b) Kushana

Question 5.
In the Gandhara art school images of _______ were mainly carved.
(a) Gautam Buddha
(b) Vardhaman Mahavir
(c) Guru Nanak
Answer:
(a) Gautam Buddha

Question 6.
The early coins that were minted in India were also like _________ coins.
(a) Sri lanka
(b) Chinese
(c) Greek
Answer:
(c) Greek

Question 7.
The excavations at Arikamedu in Tamil Nadu have also brought to light many articles made in ______.
(a) Afghanistan
(b) Rome
(c) China
Answer:
(b) Rome

Question 8.
______was an important port in Egypt.
(a) Funan
(b) Kolhapur
(c) Alexandria
Answer:
(c) Alexandria

Question 9.
Beside Indian goods, the _______ also conveyed Indian philosophy and science to Europe.
(a) Chinese
(b) Arabs
(c) Greeks
Answer:
(b) Arabs

Question 10.
The concept of ‘__________ ‘ is one of India’s major contributions to the world.
(a) zero
(b) one
(c) mathematics
Answer:
(a) zero

Question 11.
Sanghamitra carried a branch of the _________ tree to Sri Lanka.
(a) Banyan
(b) Bodhi
(c) Pipal
Answer:
(b) Bodhi

Question 12.
There was a great demand in India for Sri Lankan _________ and other precious stones.
(a) diamonds
(b) rubies
(c) pearls
Answer:
(c) pearls

Question 13.
The wall paintings in Sigiriya caves bear a resemblance to the paintings in the _______ caves.
(a) Ellora
(b) Ajanta
(c) Nashik
Answer:
(b) Ajanta

Question 14.
Right from the ancient times, India and __________ had established trade and cultural relations.
(a) China
(b) Maharashtra
(c) Rome
Answer:
(a) China

Question 15.
Emperor Harshavardhan had even sent an ambassador to the _______ court.
(a) Greek
(c) Roman
(c) Chinese
Answer:
(c) Chinese

Question 16.
Chinese _______ was known as .’Chinanshuka’ and was in great demand in India.
(a) pearls
(b) diamond
(c) silk
Answer:
(c) silk

Question 17.
Merchants in ancient India supplied Chinese silk to _______ countries.
(a) eastern
(b) western
(c) northern
Answer:
(b) western

Question 18.
The land route by which the silk trade was carried on, was called the ________.
(a) Silk Route
(b) Trade Route
(c) Horse Route
Answer:
(a) Silk Route

Question 19.
The Chinese Buddhist bhikkhus Fa-hien and Yuan Chwang also came to ______ through this silk route.
(a) Nepal
(b) Rome
(c) India
Answer:
(c) India

Question 20.
The bhikkhus translated many Buddhist texts into the _____ language.
(a) Chinese
(b) Japanese
(c) Prakrit
Answer:
(a) Chinese

Question 21.
People of Funan knew ______ language.
(a) Marathi
(b) Chinese
(c) Sanskrit
Answer:
(c) Sanskrit

Question 22.
Indian culture had a deep impact on the art and cultural life of ________ Asia.
(a) Southeast
(b) Southwest
(c) Northeast
Answer:
(a) Southeast

Question 23.
Dance-dramas based on stories from the two Indian epics are popular in ______ even today.
(a) China
(b) Indonesia
(c) Japan
Answer:
(b) Indonesia

Question 24.
In the later years, ______ of Lord Shiva and Vishnu were also built.
(a) caves
(b) muttas
(c) temples
Answer:
(c) temples

Answer in one sentence:

Question 1.
What has India exchanged with the outside world?
Answer:
Having developed trade relations, India began economic and cultural exchange with the outside world.

Question 2.
Who introduced India to the western world?
Answer:
The writings of the Greek historians introduced India to the western world.

Question 3.
Besides Indian goods, what did the Arabs convey to Europe?
Answer:
Besides Indian goods, the Arabs also conveyed Indian philosophy and science to Europe.

Question 4.
Who were sent to Sri Lanka to spread Buddhism?
Answer:
King Ashoka sent his son Mahendra and daughter Sanghamitra to Sri Lanka to spread Buddhism.

Question 5.
Who introduced the Bodhi tree to Sri Lanka?
Answer:
Sanghamitra carried a branch of the Bodhi tree to Sri Lanka.

Question 6.
What is similar between the caves at Ajanta and Sigiriya?
Answer:
The wall paintings at Sigiriya bear resemblance to the paintings in the Ajanta caves.

Question 7.
What provides information about the dose relations between India and Sri Lanka?
Answer:
The Sri Lankan Buddhist works ‘Dipavamsa’ and ‘Mahavamsa’ provide information about the close relations between India and Sri Lanka.

Question 8.
Who sent an ambassador to the Chinese court?
Answer:
Emperor Harshavardhan sent an ambassador to the Chinese court.

Question 9.
What gave an impetus to the spread of Buddhism in China?
Answer:
The Bhikkhus translated many Indian Buddhist texts into Chinese Language. This gave an impetus to spread of Buddhism in China.

Question 10.
In the later years, which temples were built in South-Asian countries?
Answer:
the later years, temples of Lord Shiva and Vishnu were built in south-asian countries.

Elaborate:

Question 1.
Alexandria was an important port in Egypt?
Answer:
The Arab merchants carried Indian goods up to Alexandria. From there, they were sent to the countries in Europe. Besides Indian goods, the Arabs also conveyed Indian philosophy and science to Europe. The concept of ‘zero’ is one of India’s major contribution’ to the world . It was the Arabs who introduced this Indian concept to Europe.

Balbharti Maharashtra State Board Class 7 Geography Solutions Chapter 11 Contour Maps and Landforms Notes, Textbook Exercise Important Questions and Answers.

Maharashtra State Board Class 7 Geography Solutions Chapter 11 Contour Maps and Landforms

Class 7 Geography Chapter 11 Contour Maps and Landforms Textbook Questions and Answers

1. Answer the following questions:

Question 1.
How can the distribution of the height and landform in a region be shown?
Answer:
(i) While studying different landforms on the surface of the earth, one has to consider various facets of landforms like altitude, relief, slope, direction of slope and the drainage.
(ii) For this maps prepared using mathematical survey methods are used.
(iii) These maps help us to understand the above characteristics of the landforms.

Question 2.
To whom are contour maps useful?
Answer:
(i) Contour maps are useful to mountaineers, trekkers, soldiers, defence officers.
(ii) The nature of the ground and its shape can be estimated .
(iii) Defence officers use contour maps for strategic planning.
(iv) It is possible to identify suitable site for any project from the contour map of the region.

Question 3.
What do you understand by observing contour lines?
Answer:
(i) Contour lines are isolines of height.
(ii) These are drawn by joining the places of equal altitude.
(iii) These help in identification of land forms and their altitude from sea level.
(iv) These lines also help us to understand the nature and direction of the slope.

Question 4.
How will a contour map be useful to a fanner?
Answer:
(i) It is helpful selecting the type of farming to be practiced plantation farming in hilly regions, intensive farming in low lying region.
(ii) In order to reduce the erosion of soil, trenches are dug out in the direction perpendicular to the slope of the land.
(iii) Trees are planted along such trenches. When the farmer digs out such trenches, he will be careful in maintaining the level.

2. Fill the blanks with appropriate words:

Question 1.
If the contour lines are closer to each other, the slope is ______.
Answer:
steep

Question 2.
The contour lines on the map represent ______.
Answer:
places of same altitude

Question 3.
The slope can be understood from the distance between the ______.
Answer:
contour lines

Question 4.
If the distance between two contour lines is more then the ______ is gentle.
Answer:
slope

3. Identify the landforms in the following map:

Class 7 Geography Chapter 11 Contour Maps and Landforms InText Questions and Answers

A model of the relief in an area is shown in fig. Observe it carefully and answer the following questions:

Question 1.
Which landforms do you seen in the model?
Answer:
Mountains & river valleys are seen in the model.

Question 2.
Which colours have been used on them?
Answer:
Yellow & blue colours have been used in the model.

Model of the Earth’s surface:

Question 1.
What all you seen in the map?
Answer:
We can see many contour lines on the map showing a hilly region. We can see the altitude of the hill ranges as well as its slope.

Question 2.
What is the general direction of the ranges shown in the map?
Answer:
The general direction of the ranges shown in the map is east-west

Question 3.
Towards which direction is the flat land located in the map?
Answer:
The flat land is located towards the east.

Question 4.
What are the maximum and minimum values of the lines in the map?
Answer:
The maximum value of the lines in the map is 800 & minimum value is 600.

Question 5.
What do these values indicate?
Answer:
These lines indicate the altitude of the region from the sea level.

Question 6.
Do you find any similarities in the map and the model in fig. (a)? What are those?
Answer:
The model in figure (a) & the contour line map in figure (b) are of the same region. The values of latitudes & longitudes are same on both the maps.

Question 7.
Which figure give us more information and what is that information?
Answer:
Fig. (b) Contour line map gives more information. It gives us information about the altitude of the landforms slope of the land forms with latitudes & longitudes

Question 8.
Is there any similarity between this map and the sketch map of the potato hill?
Answer:
Yes, similar to the sketch map of the potato hill,
the contour line map too is a 3D figure (Model of earth’s surface) which has been converted into a 2D map. The Contour line map is depicting contour line intervals.

Consider you have gone for mountaineering. You have to conquer a peak on the hill “A”. A map of this hill is given below. Studying the contour lines in the map, find the side from which you will reach the peak safely and easily. Mark your path on the map with a pencil.

Answer:
I will climb from eastwards to reach the peak safely as the slope eastwards is gentle and not steep. Lesser distance between the contour lines, indicates steep slope. The distance between the lines is greater eastwards, which shows the slope is more gentle on that side.

Class 7 Geography Chapter 11 Contour Maps and Landforms Additional Important Questions and Answers

Fill in the blanks:

Question 1.
Contour lines join places with the same on a map.
Answer:
altitude

Question 2.
Generally, contour lines do not _______ each other.
Answer:
cross.

Answer the following questions:

Question 1.
How are contour maps helpful to us?
Answer:
(i) Contour maps help us to understand various facets of landforms, like altitude, relief, slope, direction of slope and the drainage.
(ii) These maps are of immense use to mountaineers, trekkers, soldiers, defence officers, etc.
(iii) These maps prove to be of great use in planning of a region.

Question 2.
Contour lines generally do not cross each other. Give reason.
Answer:
(i) Contour lines join places with the same altitude on a map.
(ii) Therefore they generally do not cross each other.

Observe the model and the map given below and answer the following questions:

A 3D model is given in fig. (a) The northern part of the model shows the basin of the rivers Mula-Mutha. To its south is the Katraj. Diveghat range extending from the west to the east. Beyond that some portion of Karha basin is seen.

Question 1.
In which direction does fort Purandar lie?
Answer:
Fort Purandar lies in the south direction.

Question 2.
What is the direction of flow of the river Karha?
Answer:
River Karha flows from west to east.

Question 3.
In which parts are the hill ranges not observed?
Answer:
The hill ranges are not observed in the eastern parts.

Question 4.
Which part of the model is not seen in the map? Why?
Answer:
The Karha river & the direction of its flow, the contour height and the slope of the land are part of map & not seen in the model.

Question 5.
In which direction does the altitude of Katraj- Diveghat range decrease?
Answer:
The altitude of katraj-Diveghat range decreases from west to east.

Question 6.
In which direction are higher hill ranges located?
Answer:
Higher hill ranges are located in the southern direction.

Use your brain!

When one sees a landform on a contour map, what is the observer’s position with respect to landform? For example, a hill is shown with the help of contours on a map. From where do you think you are looking at it?
Answer:
Aerial view. From somewhere above, may be from an aeroplane or helicopter.

Balbharti Maharashtra State Board Class 8 Science Solutions Chapter 15 Sound Notes, Textbook Exercise Important Questions and Answers.

Maharashtra State Board Class 8 Science Solutions Chapter 15 Sound

Class 8 Science Chapter 15 Sound Textbook Questions and Answers

1. Fill in the blank with appropriate word:

Question a.
The region in a sound wave, with higher pressure and density is called ………….. and that with low pressure and density is called ……….. .
Answer:
The region in a sound wave, with higher pressure and density is called compression and that with low pressure and density is called rarefaction.

Question b.
Medium is …………… for generation of sound.
Answer:
Medium is needed (or necessary) for generation of sound.

Question c.
The total number of compressions and rarefactions produced per second in a sound wave is 1000. The frequency of the sound wave is ………… .
Answer:
The total number of compressions and rarefactions produced per second in a sound wave is 1000. The frequency of the sound wave is 500 Hz.
[Note: Total number: 100. ∴ 500 compressions and 500 rarefactions are produced per second.]

Question d.
Different sound notes have different ………………. .
Answer:
Different sound notes have different frequencies.

Question e.
In a loudspeaker, …………… energy is converted into ………….. energy.
Answer:
In a loudspeaker, mechanical energy is converted into sound energy.

2. Give scientific reasons:

Question a.
It is essential to change the tension in the vocal cords, as we produce different sound notes from our larynx.
Answer:
Different sound notes correspond to different frequencies. The frequency of sound depends on the tension in the vocal cords. Hence, it is essential to change the tension in the vocal cords, as we produce different sound notes our larynx.

Question b.
Astronauts on the moon cannot hear each other directly.
Answer:
Two astronauts on the moon talking to each other directly, will be unable to listen to each other, even if they are very close to each other. The moon does not have atmosphere. Since there is no medium which is necessary for generation and propagation of sound, between the astronauts, direct sound propagation between them is not possible. Therefore, the astronauts use some technology like the one used in our cell-phones to communicate with each other. The waves used in cell-phone do not need any medium for propagation.

Question c.
As the sound wave propagates from one place to the other in air, the air itself is not required to move from one place to the other.
Answer:
Propagation of sound through air occurs due to energy transfer by vibrating air molecules in one region to those in the adjacent region away from the source. The molecules simply vibrate about their mean positions. Hence, the air itself is not required to move from one place to the other.

3. How are different sound notes generated in musical instruments like guitar, which uses strings for sound generation, and flute, which uses blown air for sound generation?

Question a.
How are different sound notes generated in musical instruments like guitar, which uses strings for sound generation, and flute, which uses blown air for sound generation?
Answer:
1. Guitar: It is a string based, flat- backed instrument. It has usually six strings, the strings are plucked or strummed with the fingers or a small piece of plastic, wood, etc. It has a flat sounding board with a circular sound hole in the centre. Also it has a fretted fingerboard. Its frequency range is more than three octaves. The frequency of vibration of the string is changed by changing the tension in the string or changing the vibrating length of the string. As the tension is increased, the frequency increases. As the vibrating length is increased, the frequency decreases. This is how different sound notes are generated.
[Note: The acoustic guitar has hollow body and six or twelve strings while the electric guitar usually has solid body and six strings. The electric bass guitar has four strings.]

2. Flute: It is a wind instrument where air is blown against the edge or rim of the blowing hole. The frequency of the sound produced depends upon the length of the vibrating air column in the tube. The greater the length of the vibrating air column, the less is the frequency of the sound produced. This is how different sound notes are produced. The flute has six or seven or eight holes to generate sounds of different frequencies. Different notes can be generated also by changing the way of air-blowing.

4. How is sound produced in the human larynx and a loudspeaker?

Question a.
How is sound produced in the human larynx and a loudspeaker?
Answer:
1. Sound production in the human larynx:
In the humans, sound is produced in the voice box called the larynx. It is located at the upper end of the windpipe. Two vocal cords (chords) are stretched across it with a narrow slit between them for the passage of air (Fig. 15.5). When the lungs force air through the slit, the cords start vibrating.

The frequency of the sound produced depends upon the length and thickness of the cords, and the tension in the chords. The frequency increases with the increase in tension and the more the length or the thickness of the cord, the less is the frequency. Muscles attached to the cords can make the cords tight (more tension) or loose (less tension).

2. Sound produced in a loudspeaker:
Figure shows the internal construction of a loudspeaker. Here, a coil is wound around a permanent magnet. The conical screen of the loudspeaker is attached to the coil.

When a current is passed through the coil, a magnetic field is produced. Its interaction with the permanent magnet results in the back and forth motion of the coil. The frequency and the amplitude of the motion of the coil depends on the variation in the current through the coil.

As the coil moves, the conical screen also moves back and forth. The vibrations of the screen produce sound waves in air. Very loud sound can be produced by changing the current.
[Note: If you gently touch the vibrating screen, you can feel the vibrations.]

5. Explain the experiment, with0 a neat diagram, to prove the following:
‘Sound needs a material medium for propagation.’

Question a.
Explain the experiment, with0 a neat diagram, to prove the following:
‘Sound needs a material medium for propagation.’
Answer:

Figure shows part of the set up used in this experiment. What is not shown is the electric circuit in which the electric bell is connected. A vacuum tight bell jar contains an electric bell connected to a power supply through the lid of the jar. The jar is placed on a smooth horizontal surface such as that of glass.

Initially the vacuum pump is off and the jar contains air. The circuit containing the bell is completed using the key or the switch so that the bell starts ringing. This can be heard outside the jar.

Then the vacuum pump is switched on so that it starts removing the air from the jar. We find that the level of ringing sound heard goes on decreasing as the quantity of air in the jar becomes less and less.

When the pump is operated for a sufficiently long time interval, the quantity of air in the jar becomes so less that the level of ringing sound becomes very low; sound is hardly audible. But we can see the striker in the bell hitting the gong. By extrapolation, we conclude that sound generation and propagation needs a medium.

6. Match the following:

Question a.

Answer:

Column I	Column II
Human larynx	Vibrations in vocal cords
Loudspeaker	Vibrations of screen
Jaltarang	Vibrations in air column
Tuning fork	Vibrations of metal arms
Sitar	Vibrations in strings

Can you recall?

Question a.
How is sound produced?
Answer:
Sound is produced by the vibrations of an object such as a stretched membrane or a string under tension.

Project:

Question 1.
Take two plastic glasses and tie a thread between them to make a toy phone. Does the voice of your friend reach you through the thread? Take metal wire instead of the thread and also change the length of the thread wire and repeat the activity. Discuss with your friends and teacher about your conclusions.

Question 2.
Take a plastic or tin can or a plastic glass. Remove its bottom. Stretch a piece of rubber balloon across one end and fix it with a rubber band. Put a few grains of say ragi or bajra on the stretched rubber. Now ask your friend to shout ‘Hoorrey ……… Hoorrey ………… ‘ from the open end of the glass. Observe the dancing of the grains up and down. Discuss the reason behind this.

Class 8 Science Chapter 15 Sound Important Questions and Answers

Select the correct option and write the completed statements:

Question 1.
Sound waves cannot travel through a ………… .
(a) solid
(b) liquid
(c) gas
(d) vacuum
Answer:
Sound waves cannot travel through a vacuum.

Question 2.
If the frequency of a sound wave is 512 Hz, the number of rarefactions produced per second is ……………… .
(a) 256
(b) 512
(c) 1024
(d) 128
Answer:
If the frequency of a sound wave is 512 Hz, the number of rarefactions produced per second is 512.

Question 3.
In the experiment to show that a medium is necessary for propagation of sound, as the quantity of air inside the bell jar decreases, the level of ringing sound heard outside ……………… .
(a) increases
(b) decreases
(c) fluctuates randomly
(d) changes at regular intervals
Answer:
In the experiment to show that a medium is necessary for propagation of , sound, as the quantity of air inside the bell jar decreases, the level of ringing sound heard outside decreases.

Find the odd one out and give the reason:

Question 1.
Sound waves, Waves on the surface of water, Waves on a stretched string, Light waves
Answer:
Light waves. Light waves can travel in a vacuum. Other waves need a medium for propagation.

Question 2.
Sitar, Violin, Guitar, Flute.
Answer:
Flute. It is not a string based instrument. Others are string based instruments.

State whether the following statements are True or False. (If a statement is false, correct it and rewrite it.)

Question 1.
If the vibrating length of a stretched string is kept constant and the tension in the string is increased, the frequency of the sound produced increases.
Answer:
True.

Question 2.
In Jaltarang, the frequency of sound produced is independent of the height of the air column inside the glass cup.
Answer:
False. (In Jaltarang, the frequency of sound produced depends on the height of the air column inside the glass cup; the more the height of the air column, the less is the frequency of the sound produced.)

Answer the following questions in one sentence each:

Question 1.
What is sound?
Answer:
Sound is a form of energy which produces sensation of hearing in our ears.

Question 2.
What is vibration?
Answer:
Vibration is a rapid, to and from periodic motion of an object about its mean position.

Question 3.
What is compression?
Answer:
As a sound wave travels through air, the region in which air is at high pressure and high density is called compression.

Question 4.
What is rarefaction?
Answer:
As a sound wave travels through air, the region in which air is at low pressure and low density is called rarefaction.

Question 5.
What is the relation between the frequency of vibration and the vibrating length (or height) of the air column?
Answer:
The greater the vibrating length (or height) of the air column, the less is the frequency of vibration of the column.

Question 6.
For a particular string (given material and radius), what are the factors on which its frequency of vibration depends?
Answer:
For a particular string (given material and radius), the frequency of vibration of the string depends upon its vibrating length and the tension in the string.
[Note: in the above case, frequency is proportional to the square root of the tension and inversely proportional to the length.]

Question 7.
Name an instrument in which a stretched skin is used to produce musical sound.
Answer:
Tabla.

Answer the following questions:

Question 1.
Explain the production and propagation of sound in air.
Answer:
Let us consider production of sound by using a tuning fork. A tuning fork is made of a metal. It has a stem and two prongs (Fig). Figure (a) shows the state of air in the absence of propagation sound through it. Equally spaced vertical lines show that the average distance between the air molecules is the same everywhere. It means average pressure and average density in the regions A, B and C are the same.

Suppose the tuning fork is held vertical, its stem is fixed in a stand (not shown in the figure) and its prongs are struck lightly using a light hammer with a piece of rubber at the top. The prongs then start vibrating.
Figure (b) shows what happens when the prongs move away from each other. The air outside the prongs is compressed (layers in the region A). The pressure and density increase in this region.

Figure (c) shows what happens when the prongs move close to each other. The air molecules near the prongs move away from each other resulting in lower pressure and lower density.

This region is called rarefaction. Meanwhile, the compression produced earlier moves forward, i.e., away from the prongs because the air molecules in this region transfer their energy to the air molecules in the region B producing a compression there. The periodic formation of compression and rarefaction results in propagation of sound waves away from the prongs.

Eventually, these sound waves reach our ears, the ear-drum vibrates, and we get a sense of hearing a sound as the specific signals reach the brain.

Use your brain power:

Question a.
If sound waves are generated in air, what moves away from the source? Is it the air itself or the state of compression and rarefaction created in the air?
Answer:
If sound waves are generated in air, the state of compression and rarefaction created in the air moves away from the source.
[Note: The air does not move away from the source because air is elastic and the force due to the tuning fork varies periodically with time.]

Question 2.
Explain the term frequency of a sound wave.
Answer:
Sound travels in the form of waves. A wave consists of cycles of alternate compression and rarefaction. The number of cycles produced in the air (or any other medium) per second is called the frequency of the sound wave. It is expressed in hertz (Hz). 1 hertz = 1 cycle per second or 1 vibration per second or 1 oscillation per second.

[Note: The SI unit of frequency, the hertz, is named in honour of Heinrich Hertz (1857-94), German physicist.]

Question 3.
State the factors on which the frequency of a tuning fork depends.
Answer:
The frequency of a tuning fork depends on the dimensions of the prongs, i.e., length and thickness, and the material used for making the fork.

Try this:

Question a.
Take 6 – 7 glass cups. Arrange them in a line and fill them with water with gradually increasing water level from one end to other. Take a pencil and strike the cups sequentially. The sound generated by each cup will be different. Why is it so?
Use of ICT:
Download videos of Jaltarang from youtube and send them to your friends by email.

Answer:
When a cup is struck, waves are set up in the air column above the water level in the cup. The frequency of the generated wave depends on the height of the air column inside the glass cup. Since the water level in each glass is different, the height of the air column in each glass is also different. Therefore, the frequency of sound generated by each glass cup will also be different. So, the sound generated is different.

Question b.
An ‘app’ for measurement of sound frequency may be available on cellphones. With the help of your teacher, use the app to measure the frequency of the sound generated from each glass cup. Do you observe any relation between the frequency of generated sound and the height of the air column in the glass cup?
Answer:
Yes. The greater the height of the air column in the glass cup, the less is the frequency of the sound produced.

Question c.
This is your simple ‘Jaltarang’! Can this experiment be performed with stainless steel pots of different size?
Answer:
Do it. See what happens as the stainless steel pot itself starts vibrating producing a sound. Also see how this sound is damped by water.

Do you know?

Question a.
What are the frequencies of musical notes ‘sa’, ’re’, ‘ga’, ‘ma’, ‘pa’, ‘dha’, ‘ni’ in the ‘madhya saptak’?
Answer:

[Note: The diatonic scale:


Such a simple fraction is pleasing to the ear and is called a musical interval. Frequency ratios 2 : 1, 3 : 2, 4 : 3 are examples of musical interval.

Observe and discuss:

Question 1.
Identify the instruments and discuss sound production in them. [Students should see these musical instruments.]

Answer:

1. Sitar
2. Shehnai
3. Flute
4. Tabla
5. Santoor
6. Bugle
7. Mandoline or Mandolin
8. Saxophone.

Question i.
Sitar, Santoor and Mandoline or mandoline (String instruments):
Answer:
Vibrating strings produce the sound. The greater the tension in the string, the higher is the frequency of the sound. The greater the vibrating length and the diameter of the string, the lower is the frequency of the sound.

Question ii.
Flute, Saxophone and Shehnai (Wind instruments):
Answer:
Vibrating air column produces the sound. The greater the length of the column, the lower is the frequency of the sound.

Question iii.
Tabla (Percussion instrument):
Answer:
Vibrating skin produces the sound. The greater the tension in the skin, the higher is the frequency of the sound. The greater the thickness of the skin, the lower is the frequency of the sound.

Try this:
‘Apps’ for generation of different sound notes (sound note generator app) may be available on cellphones. With the help of your teacher, using such an app, generate sound notes listed in the table.

Vocal cords are 20 cm in length in male, about 15 cm in female and even smaller in children. Therefore the voice of male, female and children are different.
[Note: Vocal cords are 20 mm in length in male, about 15 mm in female and even smaller in children. Reference NCERT textbook Std. VIII, published in 2017.]

Question 1.
Produce a sound ‘bho … bho …’ just like a dog-barking and ‘meow … meow…’ just like a mewing cat. Carefully notice the tension on the vocal cords, when you produce these sounds. Do you feel that the tension on the vocal cords changes when you produce these two different sounds?
Answer:
Yes.

Question 2.
An ‘app’ may be available on cell-phones to measure the loudness of sound in decibel. With the help of your teacher, use the app to measure the sound level of a sound from a loudspeaker at some public place. Measure the sound level at different distances from the loudspeaker. Do you observe some relation between the distance from the loudspeaker and the sound level?
Answer:
Yes. As the distance increases, the sound level decreases.

Always remember:

We should take care that others are not disturbed when we study sound and its production. Sound pollution is a major cause affecting the environment and social health. Hence we should find ways to avoid sound pollution.