Solving the Gravitation Multiple Choice Questions of Class 11 Physics Chapter 8 MCQ can be of extreme help as you will be aware of all the concepts. These MCQ Questions on Gravitation Class 11 with answers pave for a quick revision of the Chapter thereby helping you to enhance subject knowledge. Have a glance at the MCQ of Chapter 8 Physics Class 11 and cross-check your answers during preparation.

Question 1.
A body is projected vertically from the surface of the earth of radius R with velocity equal to half of the escape velocity. The maximum height reached by the body is
(a) R
(b) R/2
(c) R/3
(d) R/4

Answer

Answer: (c) R/3

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Question 2.
When the planet comes nearer the sun moves
(a) fast
(b) slow
(c) constant at every point
(d) none of the above

Answer

Answer: (a) fast

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Question 3.
Keplers second law regarding constancy of arial velocity of a planet is a consequence of the law of conservation of
(a) energy
(b) angular momentum
(c) linear momentum
(d) none of these

Answer

Answer: (b) angular momentum

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Question 4.
The escape velocity for a body projected vertically upwards from the surface of the earth is 11km/s. If the body is projected at an angle of 45° with the vertical, the escape velocity will be
(a) 11 /√2 km/s
(b) 11√2 km/s
(c) 2 km/s
(d) 11 km/s

Answer

Answer: (d) 11 km/s

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Question 5.
The radii of the earth and the moon are in the ratio 10 : 1 while acceleration due to gravity on the earths surface and moons surface are in the ratio 6 : 1. The ratio of escape velocities from earths surface to that of moon surface is
(a) 10 : 1
(b) 6 : 1
(c) 1.66 : 1
(d) 7.74 : 1

Answer

Answer: (d) 7.74 : 1

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Question 6.
The escape velocity of a body from the surface of the earth is v. It is given a velocity twice this velocity on the surface of the earth. What will be its velocity at infinity?
(a) v
(b) 2v
(c) √2v
(d) √3v

Answer

Answer: (d) √3v

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Question 7.
The period of geostationary artificial satellite is
(a) 24 hours
(b) 6 hours
(c) 12 hours
(d) 48 hours

Answer

Answer: (a) 24 hours

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Question 8.
If the radius of the earth were to shrink by 1% its mass remaining the same, the acceleration due to gravity on the earths surface would
(a) decrease by 2%
(b) remain unchanged
(c) increase by 2%
(d) will increase by 9.8%

Answer

Answer: (c) increase by 2%

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Question 9.
The mean radius of the earth is R, its angular speed on its own axis is w and the acceleration due to gravity at earths surface is g. The cube of the radius of the orbit of a geo-stationary satellite will be
(a) r²g / w
(b) R²w² / g
(c) RG w²
(d) R²g / w²

Answer

Answer: (d) R²g / w²

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Question 10.
If escape velocity from the earths surface is 11.2 km/sec. then escape velocity from a planet of mass same as that of earth but radius one fourth as that of earth is
(a) 11.2 km/sec
(b) 22.4 km/sec
(c) 5.65 km/sec
(d) 44.8 km/sec

Answer

Answer: (b) 22.4 km/sec

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Question 11.
Geo-stationary satellite
(a) revolves about the polar axis
(b) has a time period less than that of the earths satellite
(c) moves faster than a near earth satellite
(d) is stationary in the space

Answer

Answer: (a) revolves about the polar axis

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Question 12.
If the radius of the earth were to be rease by 1% its mass remaining the same, the acceleration due to gravity on the surface of the earth will
(a) increase by 1%
(b) decrease by 2%
(c) decrease by 1%
(d) increase by 2%

Answer

Answer: (d) increase by 2%

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Question 13.
If the distance between the earth and the sun were half its present value , the number of day in a year would have been
(a) 64.5
(b) 129
(c) 182.5
(d) 730

Answer

Answer: (b) 129

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Question 14.
If the radius of the earth were to shrink by 1% its mass remaining the same, the acceleration due to gravity on the earths surface would
(a) decrease by 2%
(b) remain unchanged
(c) increase by 2%
(d) will increase by 9.8%

Answer

Answer: (c) increase by 2%

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Question 15.
If escape velocity from the earths surface is 11.2 km/sec. then escape velocity from a planet of mass same as that of earth but radius one fourth as that of earth is
(a) 11.2 km/sec
(b) 22.4 km/sec
(c) 5.65 km/sec
(d) 44.8 km/sec

Answer

Answer: (b) 22.4 km/sec

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Question 16.
The radii of the earth and the moon are in the ratio 10 : 1 while acceleration due to gravity on the earths surface and moons surface are in the ratio 6 : 1. The ratio of escape velocities from earths surface to that of moon surface is
(a) 10 : 1
(b) 6 : 1
(c) 1.66 : 1
(d) 7.74 : 1

Answer

Answer: (d) 7.74 : 1

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Question 17.
Average density of the earth
(a) is a complex function of g
(b) does not de end on g
(c) is inversely proportional to g
(d) is directly proportional to g

Answer

Answer: (b) does not de end on g

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Question 18.
An infinite number of identical point masses each equal to m are placed at points x = 1, x = 2, x = 4, x = 8m, ……. The total gravitational potential at point at x = 0 is
(a) -Gm
(b) -2Gm
(c) +2Gm
(d) infinite

Answer

Answer: (b) -2Gm

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Question 19.
A body is projected vertically from the surface of the earth of radius R with velocity equal to half of the escape velocity. The maximum height reached by the body is
(a) R
(b) R/2
(c) R/3
(d) R/4

Answer

Answer: (c) R/3

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Question 20.
A satellite is revolving around the earth in a circular orbit with a velocity of 7.07 km/s. What minimum increase in its velocity is needed to make it escape gravitational pull of earth?
(a) 4.23 km/s in the direction of its velocity
(b) 11.3 km/s in a direction perpendicular to its velocity
(c) 2.93 km/s in the direction of its velocity
(d) 4.23 km/s in a direction perpendicular to its velocity

Answer

Answer: (c) 2.93 km/s in the direction of its velocity

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