**CBSE MCQ Questions for Class 11 Physics Chapter 8 **Gravitation with Answers Pdf free download. MCQ Questions for Class 11 Physics with Answers were prepared based on the latest exam pattern. This MCQ will help you score good marks in the final exam. Gravitation Class 11 Physics MCQs are prepared for a better understanding of the concept. Gravitation Class 11 Physics MCQ is prepared by Experts of CBSE.

# Class 11 Physics Chapter 8 Gravitation MCQs

Check the multiple-choice questions for the 11th Class Physics Chapter 8 Gravitation. Select one answer out of 4 options.

## Gravitation Class 11 MCQs Questions with Answers

**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: (c) R/3

**Kepler’s second law may be stated as “under the influence of central force, in equal interval of time, position vector sweeps out equal**

(a) area

(b) None of these

(c) distance

(d) displacement

Answer: (a) area

**Assertion : If earth suddenly stops rotating about its axis, then the value of acceleration due to gravity will become same at all the places.Reason : The value of acceleration due to gravity depends upon the rotation of the earth.**

(a) Assertion is correct, reason is incorrect

(b) Assertion is incorrect, reason is correct

(c) Assertion is correct, reason is correct; reason is not a correct explanation for assertion

(d) Assertion is correct, reason is correct; reason is a correct explanation for assertion

Answer: (a) Assertion is correct, reason is incorrect

**Where will it be profitable to purchase one kilogram sugar?**(a) At equator

(b) At 40° latitude

(c) At poles

(d) At 45° latitude

Answer: (a) At equator

**Earth is flattened at poles, bulged at the equator. This is due to**

(a) the centrifugal force is more at the equator than at the poles

(b) the angular velocity of spinning about its axis is more at equator

(c) the angular velocity of spinning about its axis is less at equator

(d) earth revolves round the sun in an elliptical orbit

Answer: (a) the centrifugal force is more at the equator than at the poles

**Which of the following has minimum wavelength?**

(a) Blue light

(b) γ-rays

(c) infrared rays

(d) microwave

Answer: (b) γ-rays

**If a body of mass m is taken out from a point below the surface of earth equal to half the radius of earth, R, to a height R above the earths surface, then work done on it will be**

(a) (5/6) mgR

(b) (6/7) mgR

(c) (7/8) mgR

(d) (8/9) mgR

Answer: (c) (7/8) mgR

**The escape velocity for a body projected vertically upwards from the surface of the earth is 11 km/s. If the body is projected at an angle of 450 with the vertical, the escape velocity will be**

(a) 11/v^{2} km/s

(b) 11v^{2} km/s

(c) 2 km/s

(d) 11 km/s

Answer: (d) 11 km/s

**The value of g at a particular point is 9.8 m/sec² suppose the earth suddenly shrink uniformly to half its present size without losing any mass. The value of g at the same point (assuming that the distance of the point from the centre of the earth does not shrink) will become**

(a) 9.8 m/sec²

(b) 4.9 m/sec²

(c) 19.6 m/sec²

(d) 2.45 m/sec²

Answer: (a) 9.8 m/sec²

**A artificial satellite moving in a circular orbit around the earth has a total (kinetic + potential) energy E0. Its potential energy is**

(a) 2E0

(b) E0

(c) 1.5 E0

(d) -E0

Answer: (a) 2E0

**The speed of earth’s rotation about its axis is w. Its speed is increases to x times to make the effective acceleration due to gravity equal to zero at the equator. Then x is**

(a) 17

(b) 34

(c) 8.5

(d) 1

Answer: (a) 17

**If the distance of earth is halved from the sun, then the no. of days in a year will be**

(a) 129

(b) 730

(c) 182.5

(d) 365

Answer: (a) 2E0a) 129

**A missile is launched with a velocity less than the escape velocity. The sum of its kinetic and potential energy is**

(a) Positive

(b) Negative

(c) Zero

(d) may be positive or negative

Answer: (b) Negative

**If the earth is at one-fourth of its present distance from the sun, the duration of the year will be**

(a) one-eighth the present year

(b) one-sixth the present year

(c) one-tenth the present year

(d) half the present year

Answer: (a) one-eighth the present year

**The height of the point vertically above the earth’s surface, at which acceleration due to gravity becomes 1% of its value at the earth’s surface is (Radius of the earth = R)**

(a) 9 R

(b) 10 R

(c) 20 R

(d) 8 R

Answer: (a) 9 R

**The time – period of a satellite of earth is 5 hours. If the separation between the earth and the satellite is increased to 4 times the previous value, the new time – period will become**

(a) 10 hours

(b) 20 hours

(c) 40 hours

(d) 80 hours

Answer: (c) 40 hours

**In planetary motion**

(a) the total angular momentum remains constant

(b) the linear speed remains constant

(c) neither the angular momentum nor angular speed remains constant

(d) the angular speed remains constant

Answer: (a) the total angular momentum remains constant

**The radius of the earth is 6400 km and g = 10 m/s². In order that a body of 5 kg weighs zero at the equator, the angular speed of the earth is**

(a) 1/80 rad /s

(b) 1/400 rad /s

(c) 1/800 rad /s

(d) 1/1600 rad /s

Answer: (a) 1/800 rad /s

**Force of gravitational attraction is least**

(a) at the equator

(b) at the poles

(c) at a point in between equator and any pole

(d) None of these

Answer: (a) at the equator

**A body weighs 500 N on the surface of the earth. How much would it weight half way below the surface of the earth?**

(a) 1000 N

(b) 500 N

(c) 250 N

(d) 125 N

Answer: (c) 250 N

**A satellite is orbiting around the Earth with a period T. If the Earth suddenly shrinks to half its radius without change in mass, the period of revolution of the satellite will be**

(a) T

(b) T/2

(c) T/√2

(d) 2T

Answer: (a) T

**The time period (T) of the artificial satellite of Earth depends on the density (p) of the Earth as**

(a) T ∝ r

(b) T ∝ 1/ρ

(c) T ∝ 1/√ρ

(d) T ∝ √ρ

Answer: (c) T ∝ 1/√ρ

**A bail of weight W is thrown vertically upwards. The apparent w eight during the upward motion will be**

(a) zero

(b) more than W

(c) less than W

(d) W

Answer: (a) zero

**How much work per kilogram need to be done to shift a 1kg mass from the surface of Earth of infinity? Take acceleration due to gravity = g and radius of the Earth = R.**

(a) gR

(b) R/g

(c) g/R^{2}

(d) g/R

Answer: (a) gR

**What percentage of the potential energy is gained by the body in rising through a height equal to the radius of the Earth assuming that the gravitational potential energy of a body infinite distance away from Earth is zero.**

(a) 1%

(b) 10%

(c) 50%

(d) 20%

Answer: (c) 50%

**If the radius of the earth were to be raise 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: (d) increase by 2%

**Who among the following first gave the experimental velocity of G?**

(a) Cavendish

(b) Copernicus

(c) Brook Taylor

(d) none of these

Answer: (a) Cavendish

**The masses of two planets are in the ratio 1 : 2. Their radii are in the ratio 1 : 2. The acceleration due to gravity on the planets are in the ratio**

(a) 1 : 2

(b) 2 : 1

(c) 3 : 5

(d) 5 : 3

Answer: (a) 1 : 2

**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: (d) R²g / w²

**A satellite S is move in an elliptical orbit around the earth. The mass of the satellite is very small compared to the mass of the earth.**

(a) The acceleration of S is always directed towards the centre of the earth

(b) The angular momentum of S about the centre of the earth changes in direction, but its magnitude remains constant

(c) The total mechanical energy of S varies periodically with time

(d) The linear momentum of S remains constant in magnitude

Answer: (a) The acceleration of S is always directed towards the centre of the earth.

**The escape velocity of projection from the earth is approximately (R = 6400 km)**

(a) 7 km/sec

(b) 112 km/sec

(c) 12.2 km/sec

(d) 1.1 km/sec

Answer: (c) 12.2 km/sec