# MCQ Questions for Class 11 Physics Chapter 8 Gravitation with Answers

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

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

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

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

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

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

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

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%

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

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

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

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%

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

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%

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

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

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

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

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

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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