Samacheer Kalvi Class 8 Science Unit 8 Universe and Space Science Solutions
Welcome to NCTB Solutions. Here with this post we are going to help 8th class students by providing Solutions for Samacheer Kalvi Class 8 Science Unit 8 Universe and Space Science. Here students can easily find all the solved solution for Universe and Space Science Exercise questions. Also here our Expert Science Teacher’s solved all the questions with easily understandable language with proper guidance so that all the students can understand easily. Here on this post students will get Unit 8 Universe and Space Science exercise solutions. Here all the solutions are based on Tamil Nadu State Board latest syllabus.
Unit 8 Universe and Space Science Exercise Questions Solutions :
(I) Choose the best answer
(1) Which of the following is a celestial body?
(d) All the above
Correct Option → (d)
Here, all of the above are celestial body.
(2) Mangalyaan was sent to ___
Correct Option → (b)
Mangalyaan was sent to Mars.
(3) Chandrayaan 1 was launched on
(a) 22nd oct 2008
(b) 8th Nov 2008
(c) 22nd July 2019
(d) 22nd oct 2019
Correct Option → (a)
Chandrayaan – 1 was launched on 22nd oct 2008
(4) __ is called as red planet
Correct Option → (d)
Mars is called as red planet.
(5) Which of the following is the working principle of rockets
(a) Newton’s first law
(b) Newton’s second law
(c) Newton’s third law
(d) All of the above
Correct Option → (c)
Newton’s third law is the working principle of rockets.
(6) Cryogenic fuels are stored at
(a) Room temperature
(b) Low temperature
(c) Very low temperature
(d) Very high temperature
Correct Option → (c)
Cryogenic fuels are stored at Very low temperature.
(7) ___ was the first manned mission of NASA to go the moon
(a) Apollo – 5
(b) Apollo – 8
(c) Apollo – 10
(d) Apollo – 11
Correct Option → (b)
Apollo – 8 was the first manned mission of NASA to go the Moon.
(II) Fill in the blanks
(1) The study about stars and planets are known as ___
(2) Our sun belongs to ___ Galaxy.
(3) Mars revolves around the Sun once in ___ days.
(4) ___ is India’s first interplanetary mission.
(5) ___ was the first man to walk on the surface of the Moon.
(1) → Astronomy
(2) → Milky way Galaxy
(3) → 686.93 days
(4) → Mars orbit mission
(5) → Neil Armstrong
(III) Say true or false. If false, correct the statement
(1) The Sun and the celestial bodies form Solar system.
(2) Chandrayaan-1 was launched from Sriharikota.
(3) Mars is the smallest planet in the Solar system.
(4) PSLV and GSLV are India’s popular satellites.
(5) The propellant of a rocket is only in the form of solids.
(1) → True
(2) → True
(3) → False, because mercury is the smallest planet in the solar system.
(4) → True
(5) → False, ‘because it is in the three forms liquid, solid and cryogenic propellants.
(V) Answer briefly :
(1) What are celestial objects?
The stars, the planets, the moon, and many other objects like asteroids and comets in the sky are called celestial objects.
(2) Define galaxy.
A collection of billions of stars held together by mutual attraction is called Galaxy.
(3) What are the objectives of Chandrayaan -1?
The objective of chandrayaan -1
(a) To find the possibility of water on the moon.
(b) To find for the existence of helium-3.
(c) To make a 3- dimensional atlas of the moon.
(d) To study about the evolution of the solar system
(4) List out the objectives of Mangalyaan.
Objectives of Mangalyaan :
(a) To develop the technology required for interplanetary mission.
(b) To explore the surface of Mars.
(c) To study the constituents of the atmosphere of mars
(d) To provide information about the future possibility of life and past existence of life on the planet.
(5) What are Cryogenic Fuels?
Cryogenic fuels are the propellants in which the fuel or oxidized or both are liquefied gases and they are stored at a very low temperature. This type of fuel do not need any ignition system, they react on mixing and start their own flame.
(6) Name the Indians worked at NASA.
Kalpana Chawla and Sunita Williams are the two Indians worked at NASA
(VI) Answer in detail
(1) What are the achievements of Chandrayaan – 1?
Chandrayaan – 1 launched on 22nd oct 2008 from Satish Dhawan Space Centre in Sriharikota, andrea Pradesh with the help of PSLV. Achievements of chandrayaan – 1 as following –
(a) The discovery of presence of water molecules in the lunar soil.
(b) Chandrayaan- 1 confirmed that the moon was completely molten once,
(c) Chndrayyan -1 has recorded images of the landing site of the US space –craft Apollo -15 and Apollo -11.
(2) Explain the parts of a rocket.
Parts of rocket : A rocket is a space vehicle with a very powerful engine designed to carry people or equipment beyond Earth and out into space. There are four major parts or systems in a rocket :
(a) Structural system : it is the frame that covers the rocket. It is made up of very strong but light weight materials like titanium or aluminum. Fins are attached to some rockets at the bottom of the frame to provide stability during the flight.
(b) Payload system : payload is the object that the satellite is carrying into the orbit. It depends on the rocket’s mission. The rockets are modified to launch satellites with a wide range of mission like communications, weather monitoring ,spying, planetary exploration, and observatories.
(c) Guidance system : it guides the rocket in its path. It may include sensors, on-board computers, radars and communication equipment.
(d) Propulsion system : it takes up most of the space in a rocket .it consist of fuel tanks, pumps and a combustion chamber. There are two main types of propulsion systems. They are liquid propulsion system and solid propulsion systems. This are the four parts of rocket.
(3) Write a note on Apollo missions.
Apollo mission are the most popular missions of NASA. These mission made American Astronauts to land on the moon. It consist of totally 17 missions. Among them Apollo-8 and Apollo -11 are more remarkable. Apollo-8 was the first manned mission to go to the Moon. It orbited around the moon and came back to the Earth. Apollo – 11 was the first Man Landing Mission to the moon. It landed the Moon on 20th July 1969.
(VII) Higher Order Thinking Questions
(1) We always see one side of the Moon. Why?
We always see one side of the moon because moon is rotates around earth and when moon rotates only one side we can see therefore we always see one side of the moon.
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