# Unseen Passage

For Class 4 to Class 12

# Gravitation MCQ Class 9 Science

Please refer to Chapter 10 Gravitation MCQ Class 9 Science with answers below. These multiple-choice questions have been prepared based on the latest NCERT book for Class 9 Science. Students should refer to MCQ Questions for Class 9 Science with Answers to score more marks in Grade 9 Science exams. Students should read the chapter Gravitation and then attempt the following objective questions.

## MCQ Questions Class 9 Science Chapter 10 Gravitation

The Gravitation MCQ Class 9 Science provided below covers all important topics given in this chapter. These MCQs will help you to properly prepare for exams.

Question: A planet moving around sun sweeps out area A1 in two days, A2 in three days and A3 in six days. Then the relation between A1, A2 and A3 is

(A) 3A1 = 2A2 = A3
(B) 2A1 = 3A2 = 6A3
(C) 3A1 = 2A2 = 6A3
(D) 6A1 = 3A2 = 2A3

A

Question: If a planet existed whose mass was twice that of Earth and whose radius 3 times greater, how much will a 1 kg mass weigh on the planet?
(A) 25 N
(B) 2.17 N
(C) 1.1 N
(D) 5 N

B

Question: Choose the correct statement.
(A) Weight is a vector quantity.
(B) The weight of a body in interplanetary space is maximum.
(C) Weight increases when the bodies go up.
(D) 1 N = 1 kg m s–1

A

Question: A balloon of mass m is rising with an acceleration a. A fraction of its mass is detached from the balloon. Its acceleration will
(A) decrease
(B) increase
(C) remain the same
(D) none of these

B

Question: If the mass of the body on the surface of the earth is 50 kg, its mass at the centre of the earth is
(A) zero
(B) more than 50 kg
(C) less than 50 kg
(D) equal to 50 kg

D

Question: The mass of a body is measured to be 12 kg on the earth. If it is taken to the moon, its mass will be
(A) 12 kg
(B) 6 kg
(C) 2 kg
(D) 72 kg.

A

Question: The unit of G/g is
(A) kg m–1
(B) kg m–2
(C) m2 kg–1
(D) m kg–1

C

Question: Match the List-I and II and choose correct option below.
List-I                                        List-II
(P) r3 = T2 × constant             1. u = 0
(Q) v = gt                               2. Weight
(R) m × g                               3. Equation of motion
(S) v2 = u2 + 2gh                   4. Kepler’s law
(A) P – 4, Q – 1, R – 2, S – 3
(B) P – 4, Q – 2, R – 3, S – 1
(C) P – 2, Q – 4, R – 1, S – 3
(D) P – 1, Q – 4, R – 2, S – 3

A

Question: Two identical copper spheres of radius R are in contact with each other. If the gravitational attraction between them is F, find the relation between F and R.
(A) F ∝ R4
(B) F ∝ R3/2
(C) F ∝ R–2
(D) F ∝ R–4

A

Question: A particle is dropped from a tower 180 m high. How long does it take to reach the ground?
Take g = 10 m/s2.
(A) 2 s
(B) 6 s
(C) 5 s
(D) 8 s

B

Question: Relation between mass of body and its weight is
(A) w = mg
(B) w=m/g
(C) g = m – w
(D) w = m + g

A

Question: In figure, the line that joins a planet to the sun sweeps out areas A1, A2, A3 in times intervals 6 weeks, 3 weeks and 2 weeks respectively. How are A1, A2, A3 related?

(A) A1 = 3A2 = 2A3
(B) A1 = 2A2 = 3A3
(C) 2A1 = A2 = A3
(D) A1 = 3A2 = A3

B

Question. A ball is thrown vertically upwards. The acceleration due to gravity:
(A) is in the direction opposite to the direction of its motion
(B) is in the same direction as the direction of its motion
(C) increases as it comes down
(D) become zero at the highest point.

A

Question. When an apple falls from a tree:
(A) only earth attracts the apple
(B) only apple attracts the earth
(C) both the earth and the apple attract each other
(D) none attracts each other

C

Question. The weight of an object is :
(A) the quantity of matter it contains
(B) refers to its inertia
(C) same as its mass but is expressed in different units
(D) the force with which it is attracted towards the earth

D

Question. The earth attracts the moon with a gravitational force of 1020 N. Then the moon attracts the earth with a gravitational force of:
(A) 10–20 N
(B) 102 N
(C) 1020 N
(D) 1010 N

C

Question. The orbits of planets around the sun are:
(A) circular
(B) parabolic
(C) elliptical
(C) straight

C

Question. When the medium between two bodies changes, force of gravitation between them :
(A) will increase
(B) will decrease
(C) will change according to the environment
(D) remains same

D

Question. S.I. unit of G is :
(A) Nm2 kg–2
(B) Nm kg–2
(C) N kg2M–2
(D) Nkg m–2

A

Question. The value of G in S.I. unit is :
(A) 6.67 × 10–9
(B) 6.67 × 10–10
(C) 6.67 × 10–11
(D) 6.67 x 10–12

C

Question. Force of attraction between two bodies does not depend upon :
(A) the shape of bodies
(B) the distance between their centres
(C) the magnitude of their masses
(D) the gravitational constant

A

Question. A stone is dropped from the top of a tower. Its velocity after it has fallen 20 m is [Take g = 10 ms–2] :
(A) 5 ms–1
(B) 10 m s–1
(C) 15 m s–1
(D) 20 m s–1

D

Question. A body is thrown up with a velocity of 20 m/s. The maximum height attained by it is approximately:
(A) 80 m
(B) 60 m
(C) 40 m
(D) 20 m

D

Question. The value of universal gravitational constant:
(A) changes with change of place
(B) does not change from place to place
(C) becomes more at night
(D) becomes more during the day

B

Question. Law of gravitation is applicable for:
(A) heavy bodies only
(B) medium sized bodies only
(C) small sized bodies only
(D) bodies of any size

D

Question. When a space ship is at a distance of two earths radius from the centre of the earth, the gravitational acceleration is :
(A) 19.6 ms–2
(B) 9.8 m/s–2
(C) 4.9 m/s2
(
D) 2.45 ms–2

D

Question. The value of acceleration due to gravity (g) on earth’s surface is :
(A) 6.67 x 10–11 Nm2 kg2
(B) 8.9 m/sec2
(C) 9.8 m/sec2
(D) none of these

C

Question. Weight of an object depends on :
(A) temperature of the place
(B) atmosphere of the place
(C) mass of an object
(D) none of these

C

Question. The S.I. unit of g is :
(A) m2/s
(B) m/s2
(C) s/m2
(D) m/s

B

Question. The universal law of gravitation was proposed by :
(A) Copernicus
(B) Newton
(C) Galileo
(D) Archimedes

B

Question. The weight of a body is 120 N on the earth. If it is taken to the moon, its weight will be about:
(A) 120 N
(B) 60 N
(C) 20 N
(D) 720 N

C

Question. What happens to the acceleration due to gravity with the increase in altitude from the surface of the earth?
(A) Increases
(B) Decreases
(C) First decreases and then increases
(D) Remains same

B

Question. The acceleration due to gravity
(A) has the same value everywhere in space
(B) has the same value everywhere on the earth
(C) varies with the latitude on the earth
(D) is greater on the moon due to its smaller diameter.

C

Question. Which of the following statements is/are correct?
1. Mass of an object is the measure of its inertia.
2. Heavier the object smaller is the inertia.
3. The mass of an object is variable.
(A) Only 1
(B) 1 and 3
(C) 2 and 3
(D) 1 and 2

A

Question. A solid of density D is floating in a liquid of density d . If V is the volume of solid submerged in the liquid and Vl is the total volume of the solid, then Vl/V is equal to

A

Question. Which of the following statements is true?
(A) g is same at all places on the surface of earth.
(B) g has its maximum value at the equator.
(C) g is less at the earth’s surface than at a height above it or a depth below it.
(D) g is greater at the poles than at the equator.

D

Question. The gravitational force between two bodies varies with distance r as :
(A) 1/r
(B) 1/r2
(C) r
(D) r2

B

Question. Value of G on surface of earth is 6.673 × 10–11 Nm2 kg–2, then value of G on surface of Jupiter is :
(A) 12 × 6.673 × 10–11 Nm2 kg–2
(B)126.673× 1 0–11 Nm2 kg–2
(C) 6.673 × 10–11 Nm2 kg–2
(D) 66.673× 10–11 Nm2 kg–2

C

Question. A heavy stone falls:
(A) faster than a light stone
(B) slower than a light stone
(C) with same acceleration as light stone
(D) none of these

C

Question. Choose the correct statement :
(A) All bodies repel each other in thenuniverse.
(B) Our earth does not behave like a magnet.
(C) Acceleration due to gravity is 8.9 ms–2
(D) All bodies fall at the same rate in vacuum.

D

Question. A stone is dropped from the roof of a building takes 4s to reach the ground. The height of the building is :
(A) 19.6m
(B) 39.2 m
(C) 156.8 m
(D) 78.4 m

D

Question. The value of G in year 1900 was 6.673 × 10–11 Nm2 kg–2, The value of G in the year 2007 will be :
(
A) 6.673 × 10–9 Nm2 kg–2
(
B) 6.673 × 10–10 Nm2 kg–2
(C) 6.673 × 10–2 Nm2 kg–2
(D) 6.673 × 10–11 Nm2 kg–2

D

Question. Order of magnitude of G in S.I. unit is :
(A) 10–11
(B) 1011
(C) 10–7
(D) 107

A

Question. The type of force which exists between charged bodies is
(A) only gravitational
(B) neither gravitational nor electrical
(C) only electrical
(D) both electrical and gravitational

D

Question. The acceleration due to gravity:
(A) has the same value everywhere in space
(B) has the same value everywhere on the earth
(C) varies with the latitude on the earth
(D) is greater on moon because it has smaller diameter

C

Question. If planet existed whose mass and radius were both half of the earth, the acceleration due to gravity at the surface would be :
(A) 19.6 m/sec2
(B) 9.8 m/s2
(C) 4.9 ms–2
(D) 2.45 m/s2

A

Assertion & Reasoning Based MCQs
(A) Both assertion and reason are true, and reason is correct explanation of the assertion.
(B) Both assertion and reason are true, but reason is not the correct explanation of the assertion.
(C) Assertion is true, but reason is false.
(D) Assertion is false, but reason is true.

Question: Assertion : The value of acceleration due to gravity changes with the height, depth and shape of the earth.
Reason : Acceleration due to gravity is zero at the centre of the earth.

B

Question: Assertion : It is the gravitational force exerted by the sun and the moon on the sea water that causes to the formation of tides in the sea.
Reason : Gravitational force of attraction is a strong force.

C

Question: Assertion : Any two objects in the universe attract each other by a force called gravitational force.
Reason : The force of gravitation exerted by the earth is called gravity.

B

Question: Assertion : When distance between two bodies is doubled and also mass of each body is doubled, then the gravitational force between them remains the same.
Reason : According to Newton’s law of gravitation, force is directly proportional to the product mass of bodies and inversely proportional to square of the distance between them.

A

Question: Assertion : When a body is thrown up, the acceleration due to gravity at the topmost point is zero.
Reason : The acceleration due to gravity is always directed towards the centre of the earth for a freely falling body.

D

Question: Assertion : Universal gravitational constant G is a scalar quantity.
Reason : The value of G is same through out the universe.

B

Question: Assertion : Kepler’s second law of planetary motion is also known as Kepler’s law of areas.
Reason : The line joining the planet and the sun sweeps equal areas in equal intervals of time.

A

Question: Assertion : If we drop a stone and a sheet of paper from a balcony of first floor, then stone will reach the ground first.
Reason : The resistance due to air depends on velocity only.

C

Question: Assertion : A sheet of paper falls slower, than one that is crumpled in to a ball?
Reason : Sheet of paper has lesser weight than that is crumpled into a ball.

C

Case Based MCQs

Case I : According to universal law of gravitation, the force between two particles or bodies is directly proportional to the product of their masses and inversely proportional to the square of the distance between these particles or bodies.
Consider two bodies A and B having masses mand m2 respectively. Let the distance between these bodies be R. The force of gravitation between these bodies is given by

Where G is constant and is known as “universal gravitational constant”.
Question: Newton’s law of gravitation is vald

(A) in laboratory
(B) only on the earth
(C) only in our solar system
(D) everywhere

D

Question: Two particles of mass m1 and m2, approach each other due to their mutual gravitational attraction only. Then
(A) accelerations of both the particles are equal.
(B) acceleration of the particle of mass m1 is proportional to m1.
(C) acceleration of the particle of mass m1 is proportional to m2.
(D) acceleration of the particle of mass m1 is inversely proportional to m1.

C

Question: Gravitational force is a
(A) repulsive force
(B) attractive force
(C) neither (A) nor (B)
(D) both (A) and (B)

B

Question: How does the force of gravitation between two objects change when the distance between them is reduced to half?
(A) Force of gravitation becomes 4 times
(B) Force of gravitation becomes 9 times
(C) Force of gravitation becomes 6 times
(D) Force of gravitation becomes 12 times

A

Question: Gravitational force between two bodies is 1 N. If the distance between them is made half, what will be the force?
(A) 2 N
(B) 4 N
(C) 6 N
(D) 7 N

B

There is no atmosphere on the moon. This is because gas molecules need a certain amount of force of attraction to be retained on a heavenly body. The force of attraction of the moon is less than the required force, hence no atmosphere can exist.

Question: Mass of the moon is ………. that of earth
(A) more than
(B) less than
(C) equal to
(D) can’t say

B

Question: The value of g on moon is …….. times that of earth
(A) 1/3
(B)1/4
(C)/5
(D)1/6

D

Question: If the weight of an object is 60 kg f on earth then, its weight on moon is …….
(A) 10 kg f
(B) 20 kg f
(C) 30 kg f
(D) 40 kg f

A

All freely falling bodies fall with a uniform acceleration due to gravity. As a result, all the equations of motion for the uniformly accelerated
bodies moving in a straight line are applicable to  the freely falling bodies.

Question: The value of g is taken as positive when a body is
(A) dropped from a certain height
(B) moving in horizontal direction
(C) both (A) and (B)
(D) none of these

C

Question: During free fall, the acceleration of the object is
(A) zero
(B) non-uniform
(C) constant
(D) none of these

C

Question: Velocity of an object at maximum height in case it has been thrown vertically upward is
(A) maximum
(B) minimum
(C) zero
(D) 9.8 m s–1