RBSE Solutions for Class 6 Social Science Chapter 3 Discovery of the Universe

RBSE Solutions for Class 6 Social Science Chapter 3 Discovery of the Universe is part of RBSE Solutions for Class 6 Social Science. Here we have given Rajasthan Board RBSE Class 6 Social Science Chapter 3 Discovery of the Universe.

Board RBSE
Textbook SIERT, Rajasthan
Class Class 6
Subject Social Science
Chapter Chapter 3
Chapter Name Discovery of the Universe
Number of Questions 39
Category RBSE Solutions

Rajasthan Board RBSE Class 6 Social Science Chapter 3 Discovery of the Universe

Textbook Activity Based Questions and Answers

(Page 19)

Question 1.
What is Escape Velocity?
Answer:
To escape from the gravitational force of the earth, the velocity needed is around 11.2 kms/second and it is called the ‘escape velocity’.

Question 2.
How is escape velocity made possible?
Answer:
Escape velocity is not possible through humans. Hence, for this, powerful rockets are used. With the help of these rockets, spacecrafts are launched.

Question 3.
What is meant by launching velocity of satellites?
Answer:
The velocity (speed) required for launching an artificial satellite and making it stable in its orbit is called output or launching velocity.

Question 4.
What is the height of different satellites?
Answer:
The height of different satellites is around from 6400 kms to 36000 kms.

(Page 21)

Question 1.
Collect information about Sputnik and Apollo space mission and discuss.
Answer:
Sputnik Space Mission : Sputnik was the world’s first artificial satellite which was launched into space by the then Soviet Union in the year 1957 with the help of a rocket. Under the Soviet Space Program, first living being was sent in Sputnik- 2. This living being was a bitch named ‘Lyca’.
Apollo Space Mission – Apollo space mission was an American mission started in the year 1969. Three astronauts were successfully sent into space in Apollo 11 spacecraft. Out of these, two astronauts were landed on the surface of the moon. Neil Armstrong was one of them, who became the world’s first person to set his foot on the surface of the moon.

Question 2.
Who is your favourite astronaut? Write a small note on him/her and read the same in the class.
Answer:
Kalpana Chawla is my favourite astronaut. She was bom in Kamal in the state of Haryana in 1961 AD. Kalpana Chawla was a brave astronaut and a research scientist. She was the first woman bom in India to travel into space. While returning back in Columbia spacecraft, she died in air crash in 2003 along with her six associates.

(Page 22)

Question 1.
List the advantages of artificial satellites.
Answer:
Artificial satellite is a man-made mechanical body which is established under the gravitational pull of the earth in the earth’s orbit with the help of rocket. It revolves round the earth.
Following is the list of advantages of artificial satellites:

  1. Broadcast of the waves of telephone, television, radio, etc.
  2. Prediction of natural disasters such as storms, flood, etc.
  3. Helpful in distance communication and mapping.
  4. Information about various activities associated with defense.
  5. Detailed information about agriculture, forest and water resources, so that they can be conserved.

Question 2.
Which artificial satellites have been launched by India so far into space? Collect information about any two of them.
Answer:
India has launched many satellites in the space till date. Out of these, the major ones are Bhaskar, Aryabhatta, Apple Inset, Rohini, IRS, Eduset, Himset, Gartoset, Resource set, Ocean set, GSU, The Moon craft, the Mars craft, etc.

  1. Moon Craft – This is a satellite launched by India. There is plan to collect information about the moon with the help of this satellite. This artificial satellite was launched in October 2008.
  2. Mars Craft – Spacecraft named Mars craft was launched from Satish Dhawan Space Centre situated at Sri Harikota of Andhra Pradesh in November 2013. A target of collecting information about the planet Mars with the help of this satellite has been fixed. This satellite travelled for 11 months and became successful in entering the orbit of the Mars in September 2014. This type of achievement gained in such a short time is of special significance for India on world level.

Question 3.
Collect information about biogra-phies of Bhaskaracharya II, Ptolemy or Aryabhatta.
Answer:
Biographies of all these three astronauts are given below:
Bhaskaracharya II – He was bom in 1114 AD. At the age of 36, he wrote a book named ‘Siddhanta Shiromani’. Apart from this, he wrote eight books on grammar, six books on medicine, six books on yoga, five books on mathematics, two books on astronomy. He believed that the earth is round in shape and it attracts all the things towards it due to its gravitational force. He died in 1185 AD.

Ptolemy – Ptolemy was a Greek mathematician, a geologist and a scholar of astronomy. He was bom in 100 AD and he died in around 170 AD.

Aryabhatta – He was bom in 476 AD and died in 550 AD. He was a great mathematician and astronomer. He had gained education in Pataliputra. He believed that the earth is round in shape and is not stationary. He provided important information regarding sunrise, sunset and circumference of the earth.

Textbook Exercise

Question 1.
Choose correct option
(i) When was India’s first artificial satellite launched?
(a) in 1960 AD
(b) in 1975 AD
(c) in 1947 AD
(d) in 1985 AD
Answer:
(b) in 1975 AD

(ii) In Rajasthan, the ancient Jantar – Mantar observatory is located at
(a) Udaipur
(b) Kota
(c) Jaipur
(d) Jodhpur
Answer:
(c) Jaipur

Question 2.
Fill in the blanks

1. Aryabhatta was India’s great ………… .
2. The credit of giving momentum to Indian space programme goes to ………….. .
3. The velocity required to come out of the gravitational force of the earth is ………….. kms/second.
4. …………….. is the name of first artificial satellite sent into space by India.
Answer:
1. astronomer
2. Vikram Sarabhai
3. 11.2
4. Aryabhatta

Question 3.
Write the names of main astronomers of India.
Answer:
Names of Aryabhatta, Varahamihira and Bhaskaracharya II are worth mentioning among the major astronomers of India.

Question 4.
In ancient times, from where did the space research begin in the world?
Answer:
In ancient times, beginning of the space research in the world was done in India, along with other countries including Mesopotamia, Egypt, China and Greece.

Question 5.
When and why were the pyramids of Egypt made?
Answer:
Pyramids if Egypt were made even before around 2500 BC. Major reason for making them was to gather information regarding the direction and velocity of stars.

Question 6.
Discuss the contribution of Aryabhatta to astronomical researches.
Answer:
Aryabhatta was a major Indian astronomer.
His astronomical contribution can be made in the following way :

  1. Aryabhatta believed that the earth is round.
  2. He told that the earth is not stationary, and it rotates on its axis.
  3. He calculated the circumference of the earth as about 24835 miles, which is almost equal to the calculation of modem astronomers, which is approximately 24901 miles.
  4. He reasoned out that the lunar eclipse is caused due to the shadow of the earth on the moon, which is an eternal truth.

Question 7.
What is a telescope? Write about its advantages.
Answer:
Telescope is such an instrument with the help of which we can watch distant things nearer and bigger. The telescope seeing distant celestial objects was invented by Galileo of Italy in 1610 AD. At present time, countries such as India, Russia, America, China and France, etc., have made large telescopes, with the help of which, scientists are gaining vast knowledge about space. In India, Multi Application Solar Telescope (MAST) is being used to study the sun. Scientists are inventing many new telescopes, day after day, which, by connecting with computers, are being used to conduct easy and clear studies about the celestial bodies.

Question 8.
Which mathematician and geographer of Greece calculated the actual circumference of the earth the first time?
Answer:
Eratosthenes.

Question 9.
Mention about the main astronauts of the world along with their work.
Answer:
Following is a brief description of the main astronauts of the world along with their work :

  1. Soviet Union sent the first human into space under its space mission in 1961 AD. Yuri Gagarin became the world’s first person to travel into space in the spacecraft named Vostok-1.
  2. In 1969 AD, America successfully sent three astronauts into space in the spacecraft named Apollo- 11. Neil Armstrong became the world’s first person to set foot on the surface of the moon.
  3. In 1984 AD, Rakesh Sharma from India travelled into space along with two Russian astronauts. They stayed for 8 days in Soyuz T-ll space station and conducted scientific experiments.
  4. Kalpana Chawla became the first woman astronaut born in India. She was a research scientist.
  5. Sunita Williams, an American citizen of Indian origin is the woman who spent maximum time in space.

Other Important Questions

Objective Type Questions

Question 1.
According to the scientists, which country was the first in the world to prepare a table of stars?
(a) India
(b) Soviet Union
(c) America
(d) China
Answer:
(d) China

Question 2.
The scholar who wrote ‘Siddhanta Shiromani’ is
(a) Aryabhatta
(b) Varahamihir
(c) Bhaskaracharya II
(d) Ptolemy
Answer:
(c) Bhaskaracharya II

Question 3.
In India, Sawai Jai Singh built the first observatory at
(a) Delhi
(b) Jaipur
(c) Banaras
(d) Ujjain
Answer:
(a) Delhi

Question 4.
World’s first satellite was launched in the year
(a) 1949 AD
(b) 1957 AD
(c) 1961 AD
(d) 1967 AD
Answer:
(b) 1957 AD

Question 5.
First living creature to be sent into space was a
(a) Mouse
(b) Cat
(c) Bitch
(d) Sparrow
Answer:
(c) Bitch

Match the following

1. Pyramids a. Punjab (India)
2. Aryabhata b. Italy
3. Ptolemy c. Solar telescope
4. Galileo d. Egypt
5. MAST e. Greece
6. Rakesh Sharma f. Indian satellite

Answer:
1. (d), 2. (f), 3. (e), 4. (b), 5. (c), 6. (a).

Fill in the blanks

1. Pyramids have been built to study the ………… of stars.
2. In China, beginning of astronomical science is considered to be from the …………….. century.
3. Aryabhatta reasoned out that the lunar eclipse is caused due to ……………… the of the earth on the moon.
4. The development of the knowledge about space gained ground in Greece also in around ………… century BC.
5. ………….. is the main apparatus of a modem observatory.
Answer:
1. direction and velocity
2. sixth
3. shadow
4. 4th
5. Telescope

Very Short Answer Type Questions

Question 1.
Write the names of major Greek philosophers. What was their ancient assumption regarding the earth and the sun?
Answer:
Pluto, Aristotle and Ptolemy were major Greek philosophers. They believed that the earth is at the centre and the sun revolves around it in circular motion.

Question 2.
What was the belief of Bhaskaracharya II regarding the earth?
Answer:
Bhaskaracharya II believed that the earth is round in shape and due to its gravitational force, it attracts everything towards itself.

Question 3.
What was the mayor contribution of India astronomers? Write in brief.
Answer:
Indian astronomers founded the theory of gravitational force of the earth, rotation and revolution of the earth many centuries earlier than Newton.

Question 4.
Which is the biggest telescope of the country and where is it built ?
Answer:
Multi Application Solar Telescope (MAST) is the biggest telescope of the country and it is situated on an island present in Fatehsagar Lake of Udaipur city in Rajasthan.

Question 5.
At which places have major observatories in India been built?
Answer:
In India, major observatories have been built at Delhi, Jaipur, Banaras, Ujjain and Mathura. Besides these Pataliputra and Nalanda have been major regions of ancient observatories.

Question 6.
What is an artificial satellite? Explain.
Answer:
An artificial satellite is a man-made mechanical body, which is established under the gravitational force of the earth in the earth’s orbit with the help of rocket.

Question 7.
Who established Indian Space Research Organization (ISRO) and when?
Answer:
Indian Space Research Organziation (ISRO) was established in the year 1962 AD under the leadership of the famous Indian scientist Homi Jehangir Bhabha.

Question 8.
Where and when was India’s first space observatory established?
Answer:
Astrosat is the name of India’s first space observatory. It was launched from Sri Harikota by ISRO in October, 2015.

Question 9.
Which are the nations to establish space observatories prior to India?
Answer:
United States of America, Russia, Japan and European countries are included in the nations which have established space observatories prior to India.

Short Answer Type Questions

Question 1.
Describe the contribution of Greek astronomers in providing knowledge associated with space in brief.
Answer:
Beginning of space science in western countries is regarded to be beginning in Greece. The development of knowledge about space is regarded to be started in the 4th century BC over here. Pluto, Aristotle and Ptolemy were the major Greek astronomers. At that time, it was believed that the earth is at the centre and the sun revolves round it in path. This belief was proved to be wrong by the Greek scholar Copernicus. The actual circumference of earth was calculated by Greek geologist and mathematician Eratosthenes.

Question 2.
Describe the contribution of Sawai Jai Singh in space science in brief.
Answer:
In ancient time, observatories had been established in Pataliputra and Nalanda. Sawai Jai Singh extended significant contribution in establishing of observatories. On the basis of knowledge derived from China, Babylon and Europe, he started building observatories. Among these, the first observatory was Jantar – Mantar in Delhi. He got constructed the first observatory in Delhi in 1724. The second observatory was built in Jaipur in 1734 AD. Apart from these, he also got constructed observatories in Banaras, Ujjain and Mathura. Apart from

observatories, he invented three new scientific instruments – Samrat Yantra, Jai Prakash Yantra and Ram Yantra. These instruments are capable of telling time even today.

Question 3.
Give a brief description of Mars Mission conducted by India.
Answer:
In order to obtain information about the planet Mars, India launched a spacecraft named Mars craft in November 2013. It was launched from Satish Dhawan Space Centre situated in Sri Harikota (Andhra Pradesh). This spacecraft travelled for 11 months and successfully entered the orbit of Mars in September 2014. India is the world’s only country to become successful in doing this in the first attempt.

Long Answer Type Questions

Question 1.
Throw light on the use of telescopes in context to space knowledge.
Answer:
Telescope is the main apparatus of modem observatories. With its help, distant things appear to be nearer and bigger. Use of telescopes in context to ever-new information regarding the space can be explained in the following manner-

  1. The first telescope was invented by Hans Lippershey also known as Johann Lippershey or Lipperhey of Holland (Netherlands
  2. Telescope to see distant celestial objects was invented by Galelio of Italy in 1610 AD.
  3. Study of the sun is being conducted with the help of Multi Application Solar Telescope (MAST).
  4. In south India, a telescope named Venu Bapu has been established in Kavloore (Tamil Nadu).
  5. To know about the mysteries of space, scientists established “Hubble” telescope into space in 1990.

At present, telescopes are being connected to computers to conduct easy and clear study of celestial objects.

Question 2.
Write a short note on the development of space research in India.
Answer:
For the development of space research in India, the Atomic Energy Department of India established the Indian Space Research Organization (ISRO) under the leadership of Homi Jehangir Bhabha in 1962 AD. Vikram Sarabhai has played important role in the development of Indian space research programme, Many artificial satellites have been established in the earth’s orbit by Indian scientists. The first artificial satellite – Aryabhatta – was launched from Bakanoor space centre in the erstwhile Soviet Union a in the year 1975. From then up till now, many satellites have been launched into space.

Among these satellites, Bhaskar, Apple Insat, Rohini, IRS, Edusat, Himsat, Cartosat, Resource sat, Ocean sat, GSU, Moon Craft, Mars Craft are the major ones. A satellite named Moon Craft was launched in October 2008, in order to study the moon. In November 2013, a satellite named Mars Craft was launched in order to obtain information about the planet Mars and this satellite successfully entered into the orbit of Mars in September 2014. India has launched its first space observatory “Astro SAT” in space from Sri Harikota in October 2015. This will provide new information about the universe.

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