# Gravitation VBQs Class 11 Physics

VBQs Gravitation Class 11 Physics with solutions has been provided below for standard students. We have provided chapter wise VBQ for Class 11 Physics with solutions. The following Gravitation Class 11 Physics value based questions with answers will come in your exams. Students should understand the concepts and learn the solved cased based VBQs provided below. This will help you to get better marks in class 11 examinations.

## Gravitation VBQs Class 11 Physics

Question. If angular momentum of a satellite of mass m revolving around earth in a circular orbit of radius r is L, then its total energy is
(a) L2/2m
(b) –L2/2m
(c) –L2/2m2r
(d) –L2/mr

B

Question. Choose the correct relationship for a model in which a lighter particle is moving around a heavier particle only under the influence of gravitational field. Here K=kinetic energy, U=potential energy, E=total energy of the revolving particle

A

Question. The gravitational field due to mass distribution is E = A/x2 in x-direction. Here, A is constant. Taking the gravitational potential to be zero at infinity, potential at x is
(a) 2A /x
(b) 2A /x3
(c) A /x
(d) A /2×2

C

Question. If a rocket is fired with a speed v = 2 √gR near the earth’s surface, then its speed in the interstellar space is
(a) 14 √gR
(b) √2gR
(c) √gR
(d) √4gR

B

Question. Three masses each of 1 kg are placed at the corners of an equilateral triangle of side 1m. The force on the mass of 2kg which is placed at the centre of the triangle (G = 6.67 × 10–11 Nm2/kg)

(a) G(c) N
(b) G N
(c) √3/2 GN
(d) Zero

D

Question. A satellite of mass m revolving around the earth in a circular orbit of radius 2R has to be shifted to another circular orbit of radius 4R. The energy required for this process will be (M → mass of earth, R → radius of the earth)
(a) GMm /8R
(b) 2GMm /3R
(c) GMm /4R
(d) GMm /6R

A

Question. Two point masses m1 and m2 are initially rest at infinite distance apart. They start moving towards each other under their mutual gravitational forces.
Their relative speed when they are at a distance d apart is

B

Question. A satellite of mass m initially at rest on the surface of the earth is to be launched into a circular orbit at a height equal to the radius R of the earth. The minimum energy required is : (M = mass of earth)
(a) GMm/2R
(b) GMm/R
(c) GMm/4R
(d) 3/4 GMm/R

D

Question. If a satellite revolves around the earth in a circular orbit of radius r and density of earth is ρ, then its time period is directly proportional to
(a) r3
(b) r–3/2 ρ–1/2
(c) r3/2 ρ–1/2
(d) r1/2 ρ1/2

C

Question. If earth suddenly shrinks keeping mass constant and its volume becomes 8 1 of its present volume, the acceleration due to gravity on the surface of earth will increase by
(a) 50%
(b) 100%
(c) 200%
(d) 300%

D

Question. Isolated uniform hollow sphere of mass M and radius R has a point mass m placed at its centre as shown in figure. Find out the work done in moving the point mass from the centre to a point A

(a) Gm M/R
(b) 2 Gm M/R
(c) –2 Gm M/R
(d) Zero

D

Question. With what kinetic energy a particle of mass m must be thrown vertically up from earth surface so that it rises upto a maximum height of h = R, where R is radius of earth? Acceleration due to gravity near earth surface is g
(a) 2 mgR
(b) mgR
(c) 0.5 mgR
(d) 0.25 mgR

C

Question. A body of mass m is located in between two heavy body (planets) of masses M1 and M2 as shown in figure

A

Question. A uniform solid sphere of mass M and radius a is surround symmetrically by a uniform thin spherical shell of equal mass and radius 2a shown in figure.
The gravitational field at a distance 3/2 a from the centre is

(a) Zero
(b) 25GM/36a2
(c) 4GM/9a2
(d) GM/4a2

C

Question. The period of revolution of a certain planet in a orbit of radius R is T. Its period of revolution in an orbit of radius 4R will be
(a) 2T
(b) 2√2T
(c) 4T
(d) 8T

D

Question. The radius of a black hole is given by [where M is  mass of black hole and c is speed of light in vacuum]
(a) 3GM/2c2
(b) GM/2c2
(c) GM/c2
(d) 2GM/2c2

D

Question. If the escape speed of an object of mass 2 kg is 20 km/s on the surface of a planet, then the gravitational potential energy of the object on the surface of planet is
(a) –200 MJ
(b) –400 MJ
(c) –600 MJ
(d) –800 MJ

B

Question. Six particles of different masses are placed at the vertices of a regular hexagon as shown in figure. The magnitude of gravitational intensity at centre O is (side of hexagon = a)

(a) Zero
(b) Gm/a2
(c) 3Gm/a2
(d) 4Gm/a2

A

Question. A body is dropped from a height equal to the radius of earth R. If acceleration due to gravity on the surface of earth is g and air resistance is neglected, then velocity with which it hits the ground is
(a) √2gR
(b) √gR
(c) √gR/2
(d) √2gR/3

B

Question. If gravitational force between satellite and planet is directly proportional to r n, where r is orbital radius of satellite, then the time period of satellite is directly proportional to
(a) r n – 1
(b) r 1–n/2
(c) r n/2
(d) r3n/2

B

Question. A planet revolves in an elliptical orbit around the sun.
In which the semi-major and semi-minor axes have lengths a and b respectively. Then time period T is

C

Question. The following diagram shows the elliptical orbit of a planet moving around the sun. If r, v, L and K are the distance of planet from sun, speed, angular momentum and kinetic energy respectively. Then for the positions ‘1’ and ‘2’ of the planet which of the following is correct?

(a) v1r2 = v2r1
(b) L1 = L2
(c) K1 = K2
(d) All of these

B

Question. If a man at the equator would weight (3/5)th of his weight at pole, then the angular speed of earth is

A

Question. A satellite which is geostationary in a particular orbit is taken to another orbit. It’s distance from center of the earth in its new orbit is 2 times that of the earlier orbit. The time period in the new orbit is
(a) 4.8 hours
(b) 48 2 hrs
(c) 24 hrs
(d) 24 2 hrs

B

Question. A tunnel is dug along a diameter of the earth. The gravitational force on a particle of mass m placed in the tunnel at a distance x from center is (Me = Mass of earth, R = radius of earth)

A

Question. The self-gravitational potential energy of a uniform spherical of mass M and radius R is
(a) –GM2/R
(b) –GM2/2R
(c) –3/5 GM2/R
(d) –GM2/4R

C

Question. If a body be projected vertically upward from the surface of the earth so as to reach a height nR above the surface, the increase in its potential energy is

C

Question. A planet is moving in an elliptical orbit of eccentricity e around the sun. In the orbit if the maximum speed of the planet is v1 and the minimum speed is v2, then the ratio v1/v2 is.
(a) e
(b) (1+e /1–e)
(c) e2+1/e2–1
(d) e+1/e

B

Question. A body of mass M is divided into two parts of mass m1 and m2 such that gravitational force between them for a given separation r is maximum. Ratio m1/m2 is equal to
(a) 1 : 2
(b) 2 : 3
(c) 4 : 5
(d) 1 : 1

D

Question. A tunnel is dug in the earth which passes through the centre of the earth and crosses the earth. If a particle of mass m is dropped in the tunnel from the earth surface, then kinetic energy of the particle as it reaches the centre of the earth is (M = mass and R = radius of the earth)
(a) GMm/R
(b) 2GMm/R
(c) GMm/2R
(d) 3GMm/2R

C

Question. Suppose a narrow tunnel is dug along a diameter of earth. A particle kept at the centre of the tunnel is projected with speed v in such a way that the particle escapes earth’s gravitational field. The minimum value of v should be

(a) √gR
(b) √2gR
(c) √3gR
(d) √gR/2

C

Question. If g is acceleration due to gravity and –gR is gravitation potential on the surface of earth [R is radius of the earth], then gravitational potential at the centre of the earth will be
(a) –gR
(b) g/R
(c) –1.5 gR
(d) 1.5 gR

C

Question. The angular momentum about the centre of earth of a satellite of mass m revolving around earth in a circular orbit of radius r will be (M → mass of the earth)
(a) Zero
(b) √GMr
(c) m√GMr
(d) m2√GMr

C

Question. A spherically symmetric gravitational system of particles has a mass density
Then choose the correct statement for
E = gravitational field intensity
(a) for r > R, E = 0
(b) for r ≤ R, E ≠ 0
(c) for r ≤ R, E = 0
(d) E = 0, everywhere