# MCQ Class 9 Science Chapter 10 Gravitation

Please refer to the MCQ Questions for Class 9 Science Chapter 10 Gravitation. The following Gravitation Class 9 Science MCQ Questions have been designed based on the latest syllabus and examination pattern for Class 9. Our experts have designed MCQ Questions for Class 9 Science with Answers for all chapters in your NCERT Class 9 Science book.

## Gravitation Class 9 MCQ Questions with Answers

See below Gravitation Class 9 Science MCQ Questions, solve the questions and compare your answers with the solutions provided below.

Question. An object is thrown vertically upwards with a velocity u, the greatest height h to which it will rise before falling back is given by :
(a) u/g
(b) u2/2g
(c) u2/g
(d) u/2g

B

Question. The mass of moon is about 0.012 times that of earth and its diameter is about 0.25 times that of earth. The value of G on the moon will be :
(a) less than that on the earth
(b) more than that on the earth
(c) same as that on the earth
(d) about one-sixth of that on the earth

C

Question. The value of g on the surface of the moon :
(a) is the same as on the earth
(b) is less than that on the earth
(c) is more than that on the earth
(d) keeps changing day by day

B

Question. The atmosphere consisting of a large number of gases is held to the earth by :
(a) winds
(b) clouds
(c) earth’s magnetic field
(d) gravity

D

Question. The force of attraction between two unit point masses separated by a unit distance is called :
(a) gravitational potential
(b) acceleration due to gravity
(c) gravitational field strength
(d) universal gravitational constant

D

Question. The weight of an object at the centre of the earth of radius R is :
(a) zero
(b) R times the weight at the surface of the earth
(c) infinite
(d) 1/R2 times the weight at the surface of the earth

A

Question. Two objects of different masses falling freely near the surface of moon would :
(a) have same velocities at any instant
(b) have different accelerations
(c) experience forces of same magnitude
(d) undergo a change in their inertia

A

Question. The value of acceleration due to gravity of earth :
(a) is the same on equator and poles
(b) is the least on poles
(c) is the least on equator
(d) increases from pole to equator

C

Question. The law of gravitation gives the gravitational force between :
(a) the earth and a point mass only
(b) the earth and the sun only
(c) any two bodies having some mass
(d) any two charged bodies only

C

Question. The value of quantity G in the formula for gravitational force :
(a) depends on mass of the earth only
(b) depends on the radius of earth only
(c) depends on both mass and radius of earth
(d) depends neither on mass nor on radius of earth

D

Question. Two particles are placed at some distance from each other. If, keeping the distance between them unchanged, the mass of each of the two particles is doubled, the value of gravitational force between them will become :
(a) 1/4 times
(b) 1/2 times
(c) 4 times
(d) 2 times

C

Question. Acceleration due to gravity is maximum at (R is the radius of earth)
(a) a height R/2 from the earth’s surface
(b) the centre of the earth
(c) the surface of the earth
(d) a depth R/2 from earth’s surface

C

Question. The value of G was first determined experimentally by
(a) Newton
(b) Henry Cavendish
(c) Kepler
(d) Galileo

B

Question. The value of acceleration due to gravity is high if
(a) mass and radius both are small
(b) mass is small and radius is large
(c) mass is large and radius is small
(d) mass and radius both are large
Ans : (c) mass is large and radius is small
Acceleration due to gravity,

C

Question. An apple falls towards the earth because the earth attracts it. The apple also attracts the earth by the same force. Why do we not see the earth rising towards the apple?
(a) Acceleration of the earth is very large when compared to that of apple.
(b) Acceleration of the earth is equal to that of apple.
(c) Acceleration of the earth is neither high nor too low.
(d) Acceleration of the earth is very small when compared to that of apple.

D

Question. Which of the following is correct for mass?
(a) It is a vector quantity.
(b) It is not a fundamental property of material body.
(c) It is the force with which the earth attracts a body.
(d) It is the quantity of matter contained in a body.

D

Question. The value of g is zero
(a) at the top of the atmosphere
(b) at 20 km below the surface of the earth
(c) at 20 km above the surface of the earth
(d) at the centre of the earth

D

Question. In the relation F = G × M × m/d2, the quantity G :
(a) depends on the value of g at the place of observation
(b) is used only when the earth is one of the two masses
(c) is the greatest on the surface of the earth
(d) is of the same value irrespective of the place of observation

D

Question. The gravitational force of attraction between two objects is x. Keeping the masses of the objects unchanged, if the distance between the objects is halved, then the magnitude of gravitational force between them will become :
(a) x/4
(b) x/2
(c) 2x
(d) 4x

D

Question. An apple of mass 100 g falls from a tree because of gravitational attraction between the earth and the apple. If the magnitude of force exerted by the earth on the apple be F1 and the magnitude of force exerted by the apple on the earth be F2, then :
(a) F1 is very much greater than F2
(b) F2 is very much greater than F1
(c) F1 is only a little greater than F2
(d) F1 and F2 are exactly equal

D

Question. A satellite with kinetic energy Ek is revolving round the earth in a circular orbit. How much more kinetic energy should be given to it so that it may just escape into outer space
(a) Ek
(b) 2 Ek
(c) 1/2 Ek
(d) 3 Ek

A

Question. A person sitting in a chair in a satellite feels weightless because
(a) The earth does not attract the objects in a satellite
(b) The normal force by the chair on the person balances the earth’s attraction
(c) The normal force is zero
(d) The person in satellite is not accelerated

C

Question. If g ∝ 1/R3 (instead of 1/R2),Rthen the relation between time period of a satellite near earth’s surface and radius R will be
(a) T2 ∝ R3
(b) T ∝ R2
(c) T2 ∝ R
(d) T ∝ R

B

Question. If the radius of earth’s orbit is made 1/4, the duration of an year will become
(a) 8 times
(b) 4 times
(c) 1/8 times
(d) 1/4 times

C

Question. Gravitational force is the
(a) weakest force
(b) strongest force
(c) short-range force
(d) non-central force

A

Question. When an object is thrown upward, the force of gravity is
(a) opposite to the direction of motion
(b) in the same direction as the direction of motion
(c) becomes zero at the highest point
(d) increases as it rises up

A

Question. If more force is required to bring a body into a unit acceleration, the body has
(a) less mass
(b) zero mass
(c) more mass
(d) mass is independent of force

C

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 universal constant of gravitation G has the unit
(a) N
(b) m/s2
(c) (N m2)/kg2
(d) J

B

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. 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 V’ is the total volume of the solid, then V’/V is equal to
(a) d/D
(b) D/d
(c) D/(d+D)
(d) (D+d) / D

B

Question. Where will it be profitable to purchase one kilogram sugar?
(a) At poles
(b) At equator
(c) At 45c latitude
(d) at 40c latitude

B

Question. When you put an object on a spring balance, what do you measure?
(a) Weight
(b) Force
(c) Mass
(d) Acceleration

A

Question. The equation F = Gm1m2ris valid for
(a) rectangular bodies
(b) circular bodies
(c) elliptical bodies
(d) spherical bodies

D

Question. Newton’s law of gravitation is valid
(a) in laboratory
(b) only on the earth
(c) only in our solar system
(d) everywhere

D

Question. Acceleration due to gravity is maximum at (R is the radius of earth)
(a) a height R/2 from the earth’s surface
(b) the centre of the earth
(c) the surface of the earth
(d) a depth R/2 from earth’s surface

C

Question. The value of G was first determined experimentally by
(a) Newton
(b) Henry Cavendish
(c) Kepler
(d) Galileo

B

Question. A piece of iron of density 7.8 × 103 kg/m3 and volume 100 cm3 is totally immersed in water. Calculate apparent weight in water.
(a) 6.8 N
(b) 60 N
(c) 1.2 N
(d) 10 N

A

Question. Orbital velocity of earth satellite does not depend on
(a) mass of the earth
(b) mass of the satellite
(d) acceleration due to gravity

B

Question. The value of acceleration due to gravity is high if
(a) mass and radius both are small
(b) mass is small and radius is large
(c) mass is large and radius is small
(d) mass and radius both are large

C

Question. Which of the following is correct for mass?
(a) It is a vector quantity.
(b) It is not a fundamental property of material body.
(c) It is the force with which the earth attracts a body.
(d) It is the quantity of matter contained in a body.

D

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. The type of force that exists between two charged bodies is
(a) only gravitational
(b) only electrostatic
(c) neither (a) nor (b)
(d) both (a) and (b)

D

Question. Which of the following is correct?
(a) Weight is a scalar quantity.
(b) Weight is not a fundamental quantity.
(c) Weight does not depend on acceleration due to gravity.
(d) None of these

B

Question. To an astronaut in a spaceship, the sky appears
(a) Black
(b) White
(c) Green
(d) Blue

A

Question. The figure shows the motion of a planet around the sun in an elliptical orbit with sun at the focus. The shaded areas A and B are also shown in the figure which can be assumed to be equal. If 1 t and 2 t represent the time for the planet to move from a to b and d to c respectively, then

C

Question. The period of a satellite in a circular orbit of radius R is T, the period of another satellite in a circular orbit of radius 4R is
(a) 4T
(b) T/4
(c) 8T
(d) T/8

C

Question. A sphere of mass M and radius R2 has a concentric cavity of radius R1 as shown in figure. The force F exerted by the sphere on a particle of mass m located at a distance r from the centre of sphere varies as (0 ≤ r ≤ ∞)

B

Question. Orbit of a planet around a star is
(a) A circle
(b) An ellipse
(c) A parabola
(d) A straight line

A

Question. If a body describes a circular motion under inverse square field, the time taken to complete one revolution T is related to the radius of the circular orbit as
(a) T ∝ r
(b) T ∝ r
(c) T2 ∝ r3
(d) T ∝ r4

C

Question. Two planets move around the sun. The periodic times and the mean radii of the orbits are T1 , T2 and r1 , r2 respectively. The ratio  T1 / T2 is equal to
(a) (r1 / r2 )1/2
(b) r1 / r2
(c) (r1 / r2 )2
(d)  (r1 / r2 )3/2

D

Question. The earth E moves in an elliptical orbit with the sun S at one of the foci as shown in figure. Its speed of motion will be maximum at the point

B

Question. Planetary system in the solar system describes
(a) Conservation of energy
(b) Conservation of linear momentum
(c) Conservation of angular momentum
(d) None of these

C

Question. Kepler’s second law regarding constancy of aerial 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

B

Question. A shell of mass M and radius R has a point mass m placed at a distance r from its centre. The gravitational potential energy U (r) vs r will be

C

Question. The period of revolution of planet A around the sun is 8 times that of B. The distance of A from the sun is how many times greater than that of B from the sun
(a) 2
(b) 3
(c) 4
(d) 5

C

Question. A satellite of mass m is circulating around the earth with constant angular velocity. If radius of the orbit is R0 and mass of the earth M, the angular momentum about the centre of the earth is
(a) m√GMR0
(b) m√GMR0
(c) m√GM/R0
(d) m√GM/R0

A

Question. Kepler discovered
(a) Laws of motion
(b) Laws of rotational motion
(c) Laws of planetory motion
(d) Laws of curvilinear motion

C

Question. According to one of the Kepler’s laws of planetary motion :
(a) r2 ∞ T3
(b) r ∞  T2
(c) r3 ∞  T2
(d) r3 ∞ 1/T2

C

Question. What is the value of gravitational constant G (i) on the earth, and (ii) on the moon ?

6.67 × 10–11 Nm2/kg2 (ii) 6.67 × 10–11 Nm2/kg2

Question. The weight of a body is 50 N. What is its mass ? (g = 9.8 m/s2).

5.102 kg

Question. If the weight of a body on the earth is 6 N, what will it be on the moon ?

Question. Name the property of earth which is responsible for extremely small acceleration being produced in it as a result of attraction by other small objects.

Extremely large mass of earth

Question. Which force is responsible for the moon revolving round the earth ?

Gravitational force

Question. Does the acceleration produced in a freely falling body depend on the mass of the body ?

No

Question. When an object is dropped from a height, it accelerates and falls down. Name the force which accelerates the object.

Gravitational force (of earth)

Question. What is the acceleration produced in a freely falling body of mass 10 kg ? (Neglect air resistance)

9.8 m/s2

Question. What name has been given to the force with which two objects lying apart attract each other ?

Gravitational force

Question. What type of force is involved in the formation of tides in the sea ?

Gravitational force (exerted mainly by the moon and to some extent by the sun)

Question Gravitational force (of the sun)

9.8 N

Question. Acceleration due to gravity ………. with depth below the surface of the earth.

decreases

Question. The orbit of a geostationary orbit is called ……….

parking orbit.

Question. ………… velocity of the planet is constant when it revolves in an elliptical orbit around the sun.

Areal

Question. The force of gravity between two objects is inversely proportional to the square of the ………..

distance between them

Question. The force of ……….. is the centripetal force on the moon.

gravity

Question. Acceleration due to gravity is ……….. proportional to the density of the planet.

directly

Question. The acceleration due to gravity at the surface of a planet depends on the ………. and the ………. of the planet.

Question. Weight of an object is ………. at equator than at poles.

less

Question. What force is responsible for the earth revolving round the sun ?

Gravitational force

Question. What is the weight of a 1 kilogram mass on the earth ? ( g = 9.8 m/s2).

9.8 N

Question. As the altitude of a body increases, do the weight and mass both vary ?

Weight varies ; Mass does not vary

Question. If the same body is taken to places having different gravitational field strength, then what will vary : its weight or mass ?

Weight

Question. If the mass of an object be 10 kg, what is its weight ? (g = 9.8 m/s2).

19.6 N

State whether the following statements are true or false :

Question A falling stone also attracts the earth.

True

Question The acceleration due to gravity acting on a freely falling body is directly proportional to the mass of the body.

False

Question. Force of gravity is least at the equator.

False

Question. Acceleration due gravity at poles is greater than that at equator.

True

Question. If earth suddenly stops rotating about its axis, then the value of g will be same at all the places.

True

Question. The gravitation force between a spherical shell and a point mass inside it is negative and finite.

False

Question. The orbit speed of a satellite is inversely proportional to radius of its orbit.

False

Question. Copernicus discovered that the earth moves around the sun.

True

Question. Work is to be done on the system of two particles in increasing the distance between them.

True

Question The weight of an object on the earth is about one-sixth of its weight on the moon.

False

Question The force of gravitation between two objects depends on the nature of medium between them.

False

Question The value of G on the moon is about one-sixth (1/6) of the value of G on the earth.

False

Fill in the following blanks with suitable words :

Question If the weight of a body is 6 N on the moon, it will be about…………….on the earth.

36 N

Question The acceleration due to gravity on the moon is about ……………….. of that on the earth.

one-sixth

Question The weight of an object on the earth is about ………….. of its weight on the moon.

six times

Question The value of g on the earth is about …………… of that on the moon.

six times

Question In order that the force of gravitation between two bodies may become noticeable and cause motion, one of the bodies must have an extremely large …………………..

mass

Question The weight of an object on the moon is about ………………… of its weight on the earth.

one-sixth

Read the assertion and reason carefully to mark the correct option out of the options given below:
(a) If both assertion and reason are true and the reason is the correct explanation of the assertion.
(b) If both assertion and reason are true but reason is not the correct explanation of the assertion.
(c) If assertion is true but reason is false.
(d) If the assertion and reason both are false.
(e) If assertion is false but reason is true.

Question. Assertion : For a satellite revolving very near to earth’s surface the time period of revolution is given by 1 hour 24 minutes.
Reason : The period of revolution of a satellite depends only upon its height above the earth’s surface.

A

Question. Assertion : A person sitting in an artificial satellite revolving around the earth feels weightless.
Reason : There is no gravitational force on the satellite.

C

Question. Assertion : The binding energy of a satellite does not depend upon the mass of the satellite.
Reason : Binding energy is the negative value of total energy of satellite.

E

Question. Assertion : The speed of revolution of an artificial satellite revolving very near the earth is 8 kms-1 .
Reason : Orbital velocity of a satellite, become independent of height of near satellite.

A

Question. Assertion : If earth were a hollow sphere, gravitational field intensity at any point inside the earth would be zero.
Reason : Net force on a body inside the sphere is zero.

A

Question. Assertion : The speed of satellite always remains constant in an orbit.
Reason : The speed of a satellite depends on its path.

E

Question. Assertion : Gravitational field is zero both at centre and infinity.
Reason : The dimensions of gravitational field is [LT-2].

B

Question. Assertion : We can not move even a finger without disturbing all the stars.
Reason : Every body in this universe attracts every other body with a force which is inversely proportional to the square of distance between them.

A

Question. Assertion : For the planets orbiting around the sun, angular speed, linear speed, K.E. changes with time, but angular momentum remains constant.
Reason : No torque is acting on the rotating planet. So its angular momentum is constant.

A

Question. Assertion : A body becomes weightless at the centre of earth.
Reason : As the distance from centre of earth decreases, acceleration due to gravity increases.

C

Question. Assertion : Space rockets are usually launched in the equatorial line from west to east.
Reason : The acceleration due to gravity is minimum at the equator.

B

Question. Assertion : Weight of a body on earth is equal to the force with which the body is attracted towards the earth.
Reason : Weight of a body is independent of the mass of the body.
Options:
(a) Both assertion and reason are true and reason is the correct explanation of assertion.
(b) Both assertion and reason are true but reason is not the correct explanation of assertion.
(c) Assertion is true but reason is false.
(d) Both Assertion and Reason are false.

C

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.
Options:
(a) Both assertion and reason are true and reason is the correct explanation of assertion.
(b) Both assertion and reason are true but reason is not the correct explanation of assertion.
(c) Assertion is true but reason is false.
(d) Both Assertion and Reason are false.

A

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, product of force is directly proportional to the product mass of bodies and inversely proportional to square of the distance between them.
Options:
(a) Both assertion and reason are true and reason is the correct explanation of assertion.
(b) Both assertion and reason are true but reason is not the correct explanation of assertion.
(c) Assertion is true but reason is false.
(d) Both Assertion and Reason are false.

A

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.
Options:
(a) Both assertion and reason are true and reason is the correct explanation of assertion.
(b) Both assertion and reason are true but reason is not the correct explanation of assertion.
(c) Assertion is true but reason is false.
(d) Both Assertion and Reason are false.

C

Question. Assertion : An object floats on the surface of a liquid in a beaker. The whole system is allowed to fall freely under gravity. The upthrust on the object due to the liquid is equal to the weight of the liquid displaced.
Reason : Archimedes’ principle states that the upthrust on an object due to a fluid is equal to the weight of the fluid displaced.
Options:
(a) Both assertion and reason are true and reason is the correct explanation of assertion.
(b) Both assertion and reason are true but reason is not the correct explanation of assertion.
(c) Assertion is true but reason is false.
(d) Both Assertion and Reason are false.

D

Question. Assertion : A man is sitting in a boat which floats on a pond. If the man drinks some water from the pond, the level of water in the pond will decrease.
Reason : The weight of the liquid displaced by the body is greater than the weight of the body.
Options:
(a) Both assertion and reason are true and reason is the correct explanation of assertion.
(b) Both assertion and reason are true but reason is not the correct explanation of assertion.
(c) Assertion is true but reason is false.
(d) Both Assertion and Reason are false.

D

Question. Assertion : Universal gravitational constant G is a scalar quantity.
Reason : The value of G is same through out the universe.
Options:
(a) Both assertion and reason are true and reason is the correct explanation of assertion.
(b) Both assertion and reason are true but reason is not the correct explanation of assertion.
(c) Assertion is true but reason is false.
(d) Both Assertion and Reason are false.

A

Question. Assertion : When the orbital radius of a planet is made 4 times, its time period increases by 8 times.
Reason : Greater the height above the earth’s surface, greater is the time period of revolution.
Options:
(a) Both assertion and reason are true and reason is the correct explanation of assertion.
(b) Both assertion and reason are true but reason is not the correct explanation of assertion.
(c) Assertion is true but reason is false.
(d) Both Assertion and Reason are false.

B

Question. Assertion : An object floats if it displaces an amount of liquid whose weight is greater than the actual weight of the object.
Reason : During floatation an object experiences no net force in the downward direction.
Options:
(a) Both assertion and reason are true and reason is the correct explanation of assertion.
(b) Both assertion and reason are true but reason is not the correct explanation of assertion.
(c) Assertion is true but reason is false.
(d) Both Assertion and Reason are false.

B

Question. Assertion : During a journey from the earth to the moon and back, maximum fuel is spent to overcome the earth’s gravity at take off.
Reason : Earth’s mass is much greater than that of the moon.
Options:
(a) Both assertion and reason are true and reason is the correct explanation of assertion.
(b) Both assertion and reason are true but reason is not the correct explanation of assertion.
(c) Assertion is true but reason is false.
(d) Both Assertion and Reason are false.

A

MATCHING QUESTIONS

Question.