CBSE Class 9 Science Gravitation Quiz 2

1. The atmosphere is held to the Earth by

A gravity B wind C clouds D Earth’s magnetic field

2. The force of attraction between two unit point masses separated by a unit distance is called

A gravitational potential B acceleration due to gravity C gravitational field D universal gravitational constant

3. The weight of an object at the centre of the Earth of radius R is (NCERT Exemplar)

A zero B infinite C R times the weight at the surface of the Earth D 1/R times the weight at surface of the Earth

4. An object weighs 10 N in air. When immersed fully in water, it weighs only 8 N. The weight of the liquid displaced by the object will be

A 2 N B 8 N C 10 N D 12 N

5. A girl stands on a box having 60 cm length, 40 cm breadth and 20 cm width in three ways. In which of the following cases, pressure exerted by the box will be

A maximum when length and breadth form the base B maximum when breadth and width form the base C maximum when width and length form the base D the same in all the above three cases

6. An apple falls from a tree because of gravitational attractionbetween the Earth and the apple. If F

A F is very much greater than F B F is very much greater than F C F is only a little greater than F D F and F are equal

7. The acceleration due to gravity on the Earth depends upon the

A mass of the body B mass of the Earth C shape and size of the body D volume of the body

8. When a mango falls from a mango tree then

A only the Earth attracts the mango. B only the mango attracts the Earth. C both the mango and the Earth attract each other. D both the mango and the Earth repel each other.

9. When a ship floats in sea water

A The weight of water displaced is greater than the weight of ship B The weight of water displaced is less than the weight of the ship C The weight of water displaced is equal to the weight of the ship D It displaces no water.

10. The SI unit of pressure is

A Nm B N/m C N/m D N/m