A body of mass m is placed on earth's surface. It is then taken from earth's surface to a height h = 3R, then the change in gravitational potential energy is

(A)

^{mgh}/R

(B)

^{2}/3 mgR

(C)

^{3}/4 mgR

(D)

^{mgR}/2

Question-2

A second pendulum is mounted in a rocket. Its period of oscillation decreases when the rocket

(A)

Comes down with uniform acceleration

(B)

Moves round the earth in a geostationary orbit

(C)

Moves up with a uniform velocity

(D)

Moves up with uniform acceleration

Question-3

The mean radius of earth is R, its angular speed on its own axis is ω and the acceleration due to gravity at earth's surface is g. What will be the radius of the orbit of a geostationary satellite?

(A)

(B)

(C)

(D)

Question-4

The escape velocity from earth is 11.2 km/s. If a body is to be projected in a direction making an angle 45^{o} to the vertical, then the escape velocity is

(A)

11.2 × 2 km/s

(B)

11.2 km/s

(C)

11.2/√2 km/s

(D)

11.2√2 km/s

Question-5

The largest and the shortest distance of the earth from the sun are r_{1} and r_{2}. Its distance from the sun when it is perpendicular to the major axis of the orbit drawn from the sun is

(A)

(B)

(C)

(D)

Question-6

The period of revolution of planet A around the sun is 8 times that of B. The distance of A from the sun is how many times greater than that of B from the sun?

(A)

5

(B)

4

(C)

3

(D)

2

Question-7

Two spheres of masses m and M are situated in air and the gravitational force between them is F. The space around the masses is now filled with a liquid of specific gravity 3. The gravitational force will now be

(A)

F/3

(B)

F/9

(C)

3F

(D)

F

Question-8

The escape velocity of a sphere of mass m is given by (G = universal gravitational constant, M_{e} = mass of earth and Re = radius of earth)

(A)

(B)

(C)

(D)

Question-9

For a satellite escape velocity is 11 km/s. If the satellite is launched at an angle of 60^{o} with the vertical, then escape velocity will be

(A)

11 Km/s

(B)

11√3 Km/s

(C)

^{11}/√3 Km/s

(D)

33 Km/s

Question-10

A body attains a height equal to the radius of the earth. The velocity of the body with which it was projected is

(A)

(B)

(C)

(D)

Your Score 0/10

Click here to see your answersheet and detailed track records.