Telangana SCERT Class 8 Physical Science Chapter 11 Solution – Stars And The Solar System. Here in this post we provides Class 8 Physical Science Stars And The Solar System Telangana State Board Solution. Telangana State Board English Class VIII Medium Students can download this Solution to Solve out Improve Your Learning Questions and Answers.
Telanagana State Board Class 8 Physical Science Chapter 11 Stars And The Solar System Solution:
(1) Why does pole star seems to be stationary?
Ans. Pole star seems to be stationary because the pole star is situated in the direction of the earth’s and that is why it does not apperar to move even through all stars appears that they are moving because of the rotation of the earth.
Q2. Among all 8 planets what is the special thing about earth?
Ans. The earth revolves around the sun. It is a member of the solar system. This is a planet. The earth is the only planet in the solar system on which life is known to exist.
Some special environmental conditions are responsible for the existance and continuation of life on the earth. These include just the right distance from the sun so that it has the right temperature range, the presence of water and suitable atmosphere and a blanket of ozone. Thats’s the reason behind the special thing about earth among 8 planets.
(3) How do people come to an understanding that earth is spherical?
Ans. In older days people felt that earth is flat because it looks flat. after that –
i) They assumed the shape of earth as round by observing the shadow of earth in lunar eclipse.
ii) Some sailors who started their journey in ocean, reached the same place after travelling long distance in one direction only.
iii) Observations about the movement of stars and different and different stars visible from different places on the earth also helped to think about the shape of the earth.
Through all such observations made by so many people at so many places on the earth they came to an understanding that earth is spherical. and then it is, get clearified in 1969 when man landed on the moon and observed the earths shape from the moon.
(4) How do people come to an understanding that earth rotates on its own axis?
Ans. Nicolaus Copernicus suggested that the sun is at the center of the universe and all other celestial objects are revolving around the sun.
People understand that as distance of the sun from earth is same. and also day and night and seasons are also caused by it. All these proves that earth rotate on its own axis.
Application of concepts
(1) What factors to be taken into consideration to view the pole star at your place?
Ans. The position of pole star is fixed and doesn’t change.
To locate the pole star, the following points are necessary –
i) The sky must be clear, clear sky is the first priority.
ii) A telescope is also important with its help we can see the pole star.
iii) We must have a compass to locate the direction of the pole star. Pole star always located on North direction of the sky. So it must help us.
(2) How can you find north – south direction at your place?
ans. We can know the north and south direction by observing in which direction the sun rises, Now we move our face towards the sun rise direction then our left hand side direction will be north or right hand side direction will be south. In this way we find north south direction.
But here is another was to detect north-south direction, by using a compass or naturally by seeing at pole star which is always appear in the north direction, and the opposite direction of it is south.
(3) Is it possible to see the pole star for the people who live in the southern hemisphere of the earth? Why?
Ans. No, may be it is not possible because in southern hemisphere the sky which is in northern hemisphere is not visible so they don’t see the pole star.
(4) Draw the different phases of moon. Arrange them in a order from pournami to amavasya.
(5) What are the planets you have seen in the sky? When do you observe those planets?
Ans. The plannets like – Venus, Mars, Mercury, can be seen in the sky.
Mercury is very close to the sun, so it is very difficult to observe it as most of the time it can be observed just before sunrise or just after sunset, near the horizon.
Venus appears in the western sky just after sunset. So its is called a morning or an evening star.Mars is also appears slightly reddish in morning or in sunset time.
(6) What is the use of artificial satellites in our daily life?
ans. Artificial satelites are used for many purposes. Like –
i) Artificial satelites help in radio, ph communication.
ii) They help in television and radio transmission. It also help in telecommunication.
iii) They help scientists to know more information collecting about space.
iv) They help in weather forecasting.
v) They used in many internal connections also. Remove sensing are the practical applications of artificial satellites.
(7) How do day and night occur?
Ans. Day and night occur due to rotation of earth on its own axis.
Which part of the earth is faces the sun, in that case there day occur, because of the sun light fall in there which part of earth away from the sun getting no light in there night occur.
Higher Order Thinking Questions
(2) We launched many artificial satellites around our earth for different purposes. What do you think about the impact of artificial satellites and their radiation on bio diversity?
Ans. Artificial satellites are make our lives very easier by connecting people to each other.
But there are many bad impacts on bio diversity for the radiation of artificial satellites.
Like rocket that launched into space leaves a large amount of smoky dust, which effects our bio diversity.
The radiation of artificial satellites continuously releases, so it causes heart and brain diseases. For these radiation earth environment also effected too much.
Multiple Choice Questions (MCQ)
(1.) When the moon completely covers the sun as seen from the earth is known as…
a) Partial solar eclipse
b) Total solar eclipse
c) Annular eclipse
d) Hybrid eclipse
Ans. b) Total solar eclipse
(2.) The planet which is near to earth is
Ans. b) Venus
(3) The brightest planet among all the planets
ans. b) Venus
(4.) Moon is
a) the natural satellite to earth
b) an artificial satellite to earth
c) a comet d) an asteroid
Ans. a) the natural satellite to earth
(5) The first Indian artificial satellite
b) Kalpana – I
Ans. c) Aryabhatta