CG SCERT Chhattisgarh State Board Class 8 Science & Technology Chapter 1 Sky Vision Exercises Questions and Answers.
(1.) Some stars which are bigger than the Sun, appear smaller to us .Why?
ans. Some stars which are bigger than the sun appear smaller to us because when the things are far away from us, they appear smaller to us.
(2.) One star is 3.4 light years away from the Earth. What does this mean?
Ans. One star is 3.4 years away from the Earth that means the light risen from the star will take around 3.4 years to reach at the earth.
(3.) How would you find the star, which appears to be in the north?
Ans. We know that our earth is rotating round its axis from west to east but we find the stars moving from east to west. One star, which is in the north, appears motionless. We know it by the name of pole star (Dhruvtara).
Recognize the planet according to the information given:-
a) The biggest planet.
b) The planet which has life.
c) The brightest planet.
d) The red planet.
e) The first planet discovered with the telescope.
f) The planet with three rings.
g) The planet with eight satellites.
(1.) Give short notes on:-
a.) Those heavenly bodies that could not take the shape of a planet.
Ans. Satellites, asteroids are heavenly bodies that could not take the shape of a plannet. Satellites are move around some other heavenly body. moon is the natural satellite body. moon is the natural satellite of the Earth. Asteroids are revolve round the sun in an orbit between Mars and Jupiter. Asteroid is said to be that parts of matter.
b.) Those heavenly bodies which have a long shining tail.
Ans. Comets are heavenly bodies which have a long shining tail. It is revolve round the sun. We can see them only when they are very near to the sun. Its characteristic feature is small bright head with long tail. The tail of comet always points away from the sun. Usually the comet is seen after a fixed interval of time. Hailey’s comet is one such comet which appears after 76 years. Last time it was seen in 1986.
(2.) Give the difference between meteors and meteorites.
(i) Sometimes during dark nights we may see bright lines of light in the sky, they are meteors.
(ii) Meteors are in the sky.
(i) Some meteors do not burn up completely in the atmosphere, they are meteorites.
(ii) Meteorites are on the earth.
(1.) Fill in the blanks.
a) Group of stars forming a particular shape is called _______________.
b) The heavenly body which revolve round any planet is called _______.
c) ___________ is the coldest planet.
d) The ___________ star seems to be fixed at the north direction.
e) The shape of the _______________ constellation is like a hunter.
Ans. Kal purush.
(2.) Choose the correct alternative.
(1.) The planet closest to the Sun is :- (b) Mercury.
(2.) Asteroids are found in between these planets:- (a) Mars and Jupiter.
(3.) This planet doesnot have any natural satellite:- (c) Mercury.
(4.) This is not a member of the solar system:- (d) constellations
(5.) This is not a constellation:- (d) Hailey
(1.) Why do we find the Sun to be the biggest and the brightest star?
Ans. The sun is closest to the earth that is because the sun to be biggest and the brightest star.
(2.) Why does the Pole Star appear to be stationary?
Ans. We know that our earth is rotating round its axis from west to east. The pole star is situated close to the rotation of the earth that is because the pole star appear to be stationary.
(3.) Draw diagrams of the positions of different stars in Ursa Major and Orion.
(4.) Venus is not the nearest planet to the Sun .Then why is it the brightest?
ans. Venus is the second planet from the Sun in distance. It is the brightest of all the heavenly bodies seen by us. Its brightness is due to the thick clouds in its atmosphere which reflects back about three fourths of the sunlight received by it.
(5.) How will you recognise the Pole Star?
ans. Pole star are bigger than other stars. It is situated in the north of earth and its motionless.
(6.) Write the names of the planets as per their increasing distance from the Sun.
Ans. The name of the plants as per their increasing distance from the Sun. they are – Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune.
(7.) Spell out differences between a planet and a star ?
|(i)Planets have low temperature.||(i) Stars have high temperature|
|(ii) Do not have own.||(ii) Stars have own light.|
|(iii) Plants consist solid, liquid and gases.||(iii) stars consists of matter like Hydrogen, Helium etc.|