PW

Subject : Physics Paper Set : 1

Standard : 11 Gravitation Practice Date : 22-03-2024
Total Mark : 120 Time : 0H:0M

............................................... Physics - Section A (MCQ) ...............................................

(1) The ratio of escape velocity at earth (ve ) to the escape velocity at a planet (vp ) whose radius and mean density are twice as that
of earth is
√ √
(A) 1 : 2 2 (B) 1 : 4 (C) 1 : 2 (D) 1 : 2
(2) At ..... km height from the surface of earth the gravitation potential and the value of g are −5.4 × 107 Jkg −1 and 6.0 ms−2
respectively . Take the radius of earth as 6400 km.
(A) 1600 (B) 1400 (C) 2000 (D) 2600
(3) A satellite of mass m is orbiting the earth (of radius R) at a height h from its surface. The total energy of the satellite in terms of
g0 , the value of acceleration due to gravity at the earth’s surface, is
(A) 2mg (B) − 2mg (C) 2(R+h) (D) − 2(R+h)
2 2
0R 0R mg0 R2 mg0 R2
R+h R+h
(4) Imagine earth to be a solid sphece of mass M and radius R. If the value of acceleration due to gravity at a depth d below earth’s
surface is same as its value at a height h above its surface and equal to g4 (where g is the value of acceleration due to gravity on
the surface of earth), the ratio of hd will be
(A) 4
3 (B) 3
2 (C) 2
3 (D) 1
(5) The acceleration due to gravity at a height 1 km above the earth is the same as at a depth d below the surface of earth. Then d =
......... km
(A) 4
3 (B) 3
2 (C) 2
3 (D) 2
(6) Two astronauts are floating in gravitational free space after having lost contact with their spaceship. The two will
(A) move away from each other. (B) will become stationary.
(C) keep floating at the same distance between them. (D) move towards each other.
(7) A satellite of mass m is in circular orbit of radius 3RE about earth (mass of earth ME , radius of earth RE ). How much additional
energy is required to transfer the satellite to an orbit of radius 9RE ?
(A) GME m
18RE (B) 3GME m
2RE (C) GME m
9RE (D) GME m
3RE
(8) The kinetic energies of a planet in an elliptical orbit about the Sun, at positions A, B and C are KA , KB and KC , respectively. AC
is the major axis and SB is perpendicular to AC at the position of the Sun S as shown in the figure. Then

(A) KA < KB < KC (B) KA > KB > KC (C) KB > KA > KC (D) KB < KA < KC
(9) If the mass of the Sun were ten times smaller and the universal gravitational constant were ten times larger in magnitude, which
of the following is not correct?
(A) Raindrops will fall faster. (B) Walking on the ground would become more difficult.
(D) Time period of a simple pendulum on the Earth would
(C) ′ g ′ on the Earth will not change. decrease.
(10) The variation of acceleration due to gravity g with distance d from centre of the earth is best represented by (R = Earth’s radius)
(A) (B) (C) (D)

(11) A body welghs 200 N on the surface of the earth. ......N will it weigh half way down to the centre of the earth?
(A) 150 (B) 200 (C) 250 (D) 100
(12) The work done to raise a mass m from the surface of the earth to a height h, which is equal to the radius of the earth, is
(A) mgR (B) 2mgR (C) 2 mgR
1
(D) 2 mgR
3

1
(13) A mass falls from a helght h and its time of fall t is recorded in terms of time period T of a simple pendulum. On the surface of
earth it is found that t = 2T . The entre setup is taken on the surface of another planet whose mass is half of that of earth and
radius the same. Same experiment is repeated and corresponding times noted as t′ and T ′ .
√
(A) t′ = 2T′ (B) t′ > 2T′ (C) t′ < 2T′ (D) t′ = 2T′
(14) The time period of a geostationary satellite is 24 h, at a helght 6RE (RE is radius of earth) from surface of earth. The time period of
another satellite whose helght is 2.5RE from surface will be
√ √
(A) 6 2h (B) 12 2h (C) 2.5
24
h (D) 12
25 h
(15) Assuming that the gravitational potential energy of an object at inflinity is zero, the change in potential energy (final-initial) of an
object of mass m, when to a height h from the surface of earth (of radius R ), is given
(A) − GMm
R+h
GMmh
(B) R(R+h) (C) mgh (D) GMm
R+h
(16) What is the depth at which the value of acceleration due to gravity becomes 1
n times the value that at the surface of earth?
(radius of earth = R )
(A) R
n (B) nR2 (C) R(n−1)
n
(D) Rn
(n−1)
(17) The escape velocity from the Earth’s surface is v. The escape velocity from the surface of another planet having a radius, four
times that of Earth and same mass density is :
(A) v (B) 2v (C) 3v (D) 4v
(18) A particle of mass m is projected with a velocity v = kVe (k < 1) from the surface of the earth.
′ ′

(Ve = escape velocity)

The maximum height above the surface reached by the particle is :
( )2 ( )2 R2 k Rk2
(A) R k (B) R k (C) 1+k (D) 1−k2
1−k 1+k
(19) A body of mass 60g experiences a gravitational force of 3.0N , when placed at a particular point. The magnitude of the
gravitational field intensity at that point is ..... N /kg
(A) 50 (B) 20 (C) 180 (D) 0.05
(20) Match List−I With List−II
[ ]
(a) Gravitational constant (G) (i) L2 T −2
[ ]
(b) Gravitational potential energy (ii) M −1 L3 T −2
[ ]
(c) Gravitational potential (iii) LT −2
[ ]
(d) Gravitational intensity (iv) M L2 T −2
Choose the correct answer from the options given below:
(A) (a) − (ii), (b) − (iv), (c) − (i), (d) − (iii) (B) (a) − (ii), (b) − (iv), (c) − (iii), (d) − (i)
(C) (a) − (iv), (b) − (ii), (c) − (i), (d) − (iii) (D) (a) − (ii), (b) − (i), (c) − (iv), (d) − (iii)
(21) In a gravitational field, the gravitational potential is given by, V = − K
x (J/kg). The gravitational field intensity at point (2, 0, 3) m
is
(A) + K
2 (B) − K
2 (C) − K
4 (D) + K
4
(22) Two bodies of mass m and 9m are placed at a distance R. The gravitational potential on the line joining the bodies where the
gravitational field equals zero, will be ( G = gravitational constant) :
(A) − 20Gm
R (B) − 8Gm
R (C) − 12Gm
R (D) − 16Gm
R
(23) A satellite is orbiting just above the surface of the earth with period T . If d is the density of the earth and G is the universal
constant of gravitation, the quantity Gd 3π
represents :
√
(A) T (B) T (C) T 2 (D) T 3
(24) The acceleration due to gravity on the planet A is 9 times the acceleration due to gravity on planet B. A man jumps to a height
of 2 m on the surface of A. What is the height of jump by the same person on the planet B..........m
(A) 18 (B) 6 (C) 2
3 (D) 2
9
(25) Two particles of equal mass go round a circle of radius R under the action of their mutual gravitational attraction. The speed of
each particle
√is √ √ √
(A) v = 1
2R
1
Gm (B) v = Gm
2R (C) v = 1
2
Gm
R (D) v = 4Gm
R
(26) The earth (mass = 6 × 1024 kg)) revolves round the sun with angular velocity 2 × 10−7 rad/s in a circular orbit of radius
1.5 × 108 km. The force exerted by the sun on the earth in newtons, is
(A) 18 × 1025 (B) Zero (C) 27 × 1039 (D) 36 × 1021
(27) Two sphere of mass 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 (B) F
3 (C) F
9 (D) 3 F
(28) The density of a newly discovered planet is twice that of earth. The acceleration due to gravity at the surface of the planet is
equal to that at the surface of the earth. If the radius of the earth is R, the radius of the planet would be
(A) 2R (B) 4R (C) 1
4R (D) 1
2R

2
(29) A body of mass m is placed on the earth’s surface. It is taken from the earth’s surface to a height h = 3R. The change in
gravitational potential energy of the body is
(A) 2
3 mgR (B) 3
4 mgR (C) mgR
2 (D) mgR
4
(30) The escape velocity of a sphere of mass m is given by (G = Universal gravitational constant; Me = Mass of the earth and Re =
Radius
√ of the earth) √ √
(A) 2GMe (B) GM
R 2
e
(C) 2Gm
(D) GMe
Re e Re Re

3
 PW

Subject : Physics Paper Set : 1

Gravitation Practice
Standard : 11 Date : 22-03-2024
Total Mark : 120 (Answer Key) Time : 0H:0M

Physics - Section A (MCQ)

1-A 2-D 3-D 4-A 5-D 6-D 7-C 8-B 9-C 10 - D

11 - D 12 - C 13 - D 14 - A 15 - B 16 - C 17 - D 18 - D 19 - A 20 - A
21 - C 22 - D 23 - C 24 - A 25 - C 26 - D 27 - A 28 - D 29 - B 30 - A