If the radius of the earth is reduced by 1% without changing its mass. The change in g will be

• 2% decrease

• 2% increases

• 1% decrease

• 1% increases

If the change in the value of g at a height h above the surface of the earth is the same as at a depth x below in surface, then

• x = h²

• x = 0.5 h

• x = 2h

• x = h

Radius of orbit of satellite of earth is R its kinetic energy is proportional to

• $\frac{1}{\mathrm{R}}$

• $\frac{1}{\sqrt{\mathrm{R}}}$

• R

• $\frac{1}{{\mathrm{R}}^3}$

On an electron in an atom both electric and gravitational forces are collinear we neglect gravitational force (F_G) in comparision to electric force (F_E ), because

• F_E > F_G

• F_N > F_E

• F_E >> F_G

• F_N >> F_G

The gravitational field is given by E = − xi − 2y²j. When gravitational potential is zero at (0, 0), then the gravitational potential at (2, 1) is

• 3 unit

• 6 unit

• 9 unit

• 12 unit

A satellite orbiting the earth in a circular orbit of radius R completes one revolution in 3 h. If orbital radius of geostationarysatellite is 36,000 km, orbital radius of earth is 

• 6000 km

• 9000 km

• 12000 km

• 15000 km

Acceleration due to gravity is g on the surface of the earth. Then the value of the acceleration due to gravity at a height of 32 km above earth's surface is (Assume radius of earth to be 6400 km)

• 0.99 g

• 0.8 g

• 1.01 g

• 0.9 g

If the mass of moon is $\frac{1}{90}$ of earth's mass, its radius is $\frac{1}{3}$ of earth's radius and if g is acceleration due to gravity on earth, then the acceleration due to gravity on moon is

• $\frac{\mathrm{g}}{3}$

• $\frac{\mathrm{g}}{90}$

• $\frac{\mathrm{g}}{10}$

• $\frac{\mathrm{g}}{9}$

Which of the following statements about the gravitational constant is true ?

• It is a force

• It has no unit

• It has same value in all systems of units

• It does not depend on the nature of the medium in which the bodies are kept

210.

Two identical solid copper spheres of radius R are placed in contact with each other. The gravitational attraction  between them is proportional to

• R²

• R^-2

• R⁴

• R^-4