CBSE - Gravitation

1 Gravitation How many planets are there in our solar system

(1) 5
(2) 7
(3) 9
(4) 8

2 Gravitation What are the names of the two Moons of the Mars?
(1) Titan and Sheron
(2) Titan and Demos
(3) Phobos and Demos
(4) Sheron and Phobos

3 Gravitation A planet had density P, radius R and acceleration due to gravity as g. If the radius of the planet were double keeping the density same, the acceleration due to gravity at the surface will be :

(1) 4g
(2) 2g
(3) g
(4) g/2

4 Gravitation The first Astronaut in space was -

(1) H.G. Wales
(2) Neel Armstrong
(3) Uri Gagarin
(4) Robert Godai

5 Gravitation The earth rotates about the sun in an elliptical orbit. At which point is velocity maximum?

1) At A
2) At B
3) At C
4) At D

6 Gravitation The mass of an object is 10 Kg on earth. So we can say -

(1) Its weight on earth Is 10 N.
(2) Its weight on eart h is 1. 67 N.
(3) Its weight on moon is 10 N.
(4) Its mass on moon is 10 Kq.