gravitation class 9

Newton’s law of gravitation is valid

(a) on the earth only (b) on the moon only (c) in the laboratory only (d) everywhere

• a

• b

• c

• d

When a body is thrown up, the force of gravity is

(a) in the upward direction

(b) in the downward direction

(c) zero

(d) in the horizontal direction

• a

• b

• c

• d

What happens to the acceleration due to gravity with the increase in altitude from the surface of the earth?

(a) Increases

(b) Decreases

(c) First decreases and then increases

(d) Remains same

• a

• b

• c

• d

Which of the following statements is/are correct?

1. Mass of an object is the measure of its inertia.

2. Heavier the object smaller is the inertia.

3. The mass of an object is variable.

(a) Only 1

(b) 1 and 3

(c) 2 and 3

(d) 1 and 2

• a

• b

• c

• d

The mass of a body is measured to be 12 kg on the earth. If it is taken to the moon, its mass will be

(a) 12 kg

(b) 6 kg

(c) 2 kg

(d) 72 kg

• a

• b

• c

• d

Which of the following statements is true?

(a) g is same at all places on the surface of earth.

(b) g has its maximum value at the equator.

(c) g is less at the earth’s surface than at a height above it or a depth below it.

(d) g is greater at the poles than at the equator.

• a

• b

• c

• d

The weight of a body is 120 N on the earth. If it is taken to the moon, its weight will be about

(a) 120 N

(b) 60 N

(c) 20 N

(d) 720 N

• a

• b

• c

• d

Loss of weight of a body immersed in a liquid is

(a) equal to the weight of the liquid displaced

(b) more than the weight of the liquid displaced

(c) less than the weight of the liquid displaced

(d) zero

• a

• b

• c

• d

A coin and a feather are dropped together in a vacuum. Then

(a) the coin will reach the ground first

(b) the feather will reach the ground first

(c) both will reach the ground at the same time

(d) the feather will not fall down

• a

• b

• c

• d

The mass of a body is increased 4 fold and mass of other body is increased 16 fold. How should the distance between them be changed to keep the same gravitational force between them?

(a) 4 times

(b) 4 1 times

(c) 8 times

(d) 8 1 times

• a

• b

• c

• d