Gravitation

Which one of the following statements about gravitational force is not correct?

1. It is experienced by all bodies in the universe
2. It is a dominant force between celestial bodies
3. It is a negligible force for atoms
4. It is same for all pairs of bodies in our universe

Planet A has double the radius than that of planet B. If the mass of planet A is 4 times heavier than the mass of planet B, which of the following statements regarding weight of an object is correct?

1. Heavier on Planet B than on Planet A
2. Same on both the Planets
3. Cannot be measured on Planet B
4. Heavier on Planet A than on Planet B

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

1. 2 N
2. 8 N
3. 10 N
4. 12 N

The weight of an object at the centre of the earth of radius R is

1. zero
2. infinite
3. R times the weight at the surface of the earth
4. 1/R² times the weight at surface of the earth

The value of quantity G in the law of gravitation

1. depends on mass of earth only
2. depends on radius of earth only
3. depends on both mass and radius of earth
4. is independent of mass and radius of the earth

Law of gravitation gives the gravitational force between

1. the earth and a point mass only
2. the earth and Sun only
3. any two bodies having some mass
4. two charged bodies only

The gravitational force between two objects is F. If masses of both objects are halved without changing distance between them, then the gravitational force would become

1. F/4
2. F/2
3. F
4. 2F

The value of acceleration due to gravity

1. is same on equator and poles
2. is least on poles
3. is least on equator
4. increases from pole to equator

Two objects of different masses falling freely near the surface of moon would

1. have same velocities at any instant
2. have different accelerations
3. experience forces of same magnitude
4. undergo a change in their inertia