Gravitation MCQs with Answers

Question-1. A body of mass 1kg is attracted by the earth with a force which is equal to

1. 9.8N
2. 6.67x 1011
3. 1 N
4. 9.8m/s

Question-2. A coin and a feather are dropped together in a vacuum.

1. The coin will reach the ground first.
2. The feather will reach the ground first.
3. Both will reach the ground together.correct
4. The feather will not fall down.

Question-3. A mass weighing W can float if the upthrust U is related as

1. U > W
2. U = W
3. U < W
4. U = W

Question-4. A rectangular block of wood of dimensions 40cm x 20cm x 10cm is kept on a table top. The pressure is greatest when it is rested on

1. equal for all cases
2. 20cm x 10 cm
3. 40cm x 10cm
4. 40cm x 20cm

Question-5. Acceleration due to gravity on the surface of the moon is 1/6th of its value on the surface of the earth as they have different______.

1. mass
2. density
3. radius
4. All of the above

Question-6. An apple and a stone dropped from certain height accelerates

1. equally
2. differently
3. depending on density
4. depends on the position of the sun

Question-7. An astronaut in the orbit in a spacecraft feels weightlessness

1. due to the absence of gravity inside
2. due to the fact that spacecraft has no energy
3. because acceleration in the orbit is equal to acceleration of gravity outside
4. there is no gravity outside

Question-8. An object is put in three liquids having different densities, one by one. The object floats with 1/9, 2/11 and 3/7 parts of its volume outside the surface of liquids of densities d1, d2 and d3 respectively. Which of the following is the correct order of the densities of three liquids?

1. d1 > d2 > d3
2. d2 > d3 > d1
3. d1 < d2 < d3
4. d3 > d2 > d1

Question-9. An object weighing 5 N in air, weighs 4.5 N a liquid. The buoyant force experienced by the object is

1. (5 + 4.5) N
2. 4.5/5 N
3. 5/4.5 N
4. 0.5 N

Question-10. At which of the following locations is the value of g largest?

1. On top of the Mount Everest
2. On top of Qutub Minar
3. At a place on the equator
4. A camp site in Antarctica

Question-11. Choose the correct unit for the relative density among the following

1. kg/cm
2. unitless
3. kg/cm
4. kg/m3

Question-12. If more force is required to bring a body into a unit acceleration, the body has

1. less mass
2. zero mass
3. more mass
4. mass is independent of force

Question-13. If the distance between objects increases, then the gravitational force between the objects will:

1. remain same
2. none of these
3. decrease
4. Increase

Question-14. Newtons law of gravitation is valid

1. in laboratory
2. only on the earth
3. only in our solar system
4. everywhere

Question-15. SI Unit of pressure is

1. Pascal
2. Newton
3. m/s
4. Dyne

Question-16. The acceleration due to gravity

1. has the same value everywhere in space
2. has the same value everywhere on the earth
3. varies with the latitude on the earth
4. is greater on the moon due to its smaller diameter

Question-17. The constant G

1. is a very small quantity
2. is a force
3. is the same as g
4. decrease with increasing altitude

Question-18. The earth and the moon are attracted to each other by gravitational force. The earth attracts the moon with a force that is

1. More than that exerted by the moon
2. Same as that exerted by the moon
3. Less than that exerted by the moon
4. Not related to that exerted by the moon

Question-19. The Earth attracts the moon with a gravitational force of 1020N. The moon attracts the earth with a gravitational force of

1. Less than 1020N
2. 1020N
3. Greater than 1020N
4. 10-20N

Question-20. The expression for finding the gravitational force of attraction between any two bodies is

1. F= G m1m2/r3
2. F= G m1m2/r
3. F= Gm1 m2/r2
4. F = Gm1/r

Question-21. The force acting on an object perpendicular to the surface is called

1. weight
2. Pressure
3. Weight
4. thrust

Question-22. The force which keeps the body to move in circular motion when accelerated is

1. Force of gravitation
2. Magnetic force
3. Centripetal force
4. Electrostatic force

Question-23. The gravitational force between two bodies does not depend on

1. their separation
2. their masses
3. the product of their masses
4. the medium between the two bodies

Question-24. The gravitational force causes

1. Tides
2. Motion of moon
3. None of them
4. Both a n b

Question-25. 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

1. 12 Kgcorrect
2. 6 Kg
3. 2 Kg
4. 72 Kg

Question-26. The mass of an object is

1. The amount of matter contained in the object, independent of where that object is found
2. the force of gravity on that object located at a particular point in space
3. dependent on whether the object is on the Earth or elsewhere
4. divided by the Earth acceleration due to gravity to equal force.

Question-27. The mass of moon is about 0.012 times that of the earth and its diameter is about 0.25 times that of earth. The value of G on the moon will be

1. Same as that on the earth
2. About one-fifth of that on the earth
3. About one-sixth of that on the earth
4. About one-fourth of that on the earth

Question-28. The mass of the earth is

1. 6.4 × 1024
2. 6 × 1010 kg
3. 6 × 1024 kg
4. 6 × 1019 kg

Question-29. The relation between the weight of an object on the moon (WM) and on the earth (WE)

1. WM =6 WE
2. We = 1/6WM
3. WM= We
4. WM =1/6 (We)

Question-30. The time of ascent when measured from the point of projection of a body projected upwards , the

1. Time of ascent=Time of descent
2. Time of ascent > Time of descent
3. Time of ascent < Time of descent
4. All of the above

Question-31. The upward force exerted by the liquid displaced by the body when it is placed inside the liquid is called

1. Buoyant force
2. Gravitational force
3. Centripetal force
4. Force of gravitation

Question-32. The value of acceleration due to gravity at the MountEverest is

1. g
2. > g
3. < g
4. zero

Question-33. The value of acceleration due to gravity at the poles

1. zero
2. Same as at the equator
3. Is less than at the equator
4. Is more than at the equator

Question-34. The walls of a dam at the bottom are made thick because

1. it looks attractive
2. it is conventional
3. it is convenient
4. water exerts large pressure at the bottom

Question-35. The weight of a body is 120 N on the earth. If it is taken to the moon, its weight will be about

1. 120 N
2. 60 N
3. 20 N
4. 720 N

Question-36. The weight of an object is:

1. lesser on earth and greater on moon
2. Equal on both earth and moon
3. Greater on earth and lesser on moon
4. none of these

Question-37. Two particles are placed at some distance. If the mass of each of the two particles is doubled, keeping the distance between them unchanged, the value of gravitational force between them will be

1. 1/4 times
2. 4 times
3. 1/2 times
4. Unchanged

Question-38. Universal law of gravitation does not explain

1. the tides on earth due to the moon
2. the motion of electrons in an atom
3. the motion of planets around the Sun
4. the motion of the moon around the earth

Question-39. Weight of an object is highest at

1. Center of earth
2. Poles
3. Above the earth?s surface
4. Equator

Question-40. Weight of an object on the surface of the moon is

1. 1/6 that on the surface of the earth
2. 1/5 th that on the surface of the earth
3. 1/3 that on the surface of the earth
4. 1/2 that on the surface of the earth

Question-41. What happens to the acceleration due to gravity with the increase in altitude from the surface of the earth?

1. Increases
2. Decreases
3. First decreases and then increases
4. Remains same

Question-42. When a body is thrown up, the force of gravity is

1. in the upward direction
2. in the downward direction
3. zero
4. in the horizontal direction

Question-43. When a body is weighed in a liquid, the loss in weight is equal to

1. weight of liquid displaced by the body
2. weight of water displaced by the body
3. weight of body in air
4. half the weight of body in air

Question-44. When an object is thrown upward, the force of gravity is

1. opposite to the direction of motion
2. in the same direction as the direction of motion
3. becomes zero at the highest point
4. increases as it rises up

Question-45. Which of the following statements is true?

1. g is same at all places on the surface of earth.
2. g has its maximum value at the equator.
3. g is less at the earth?s surface than at a height above it or a depth below it.
4. g is greater at the poles than at the equator

Question-46. Which of the following was NOT a contribution of Newtons to science?

1. the first good experimental measure of G, the gravitational constant of proportionality
2. the law of universal gravitation
3. F = ma
4. explanations of optical phenomena

Question-47. A boy is whirling a stone tied to a string in a horizontal circular path. If the string breaks, the stone

1. will continue to move in the circular path
2. will move along a straight line towards the centreof the circular path
3. will move along a straight line tangential to the circular path
4. will move along a straight line perpendicular to the circular path away from the boy

Question-48. A girl stands on a box having 60 cm length, 40 cm breadth and 20 cm width in three ways. In which of the following cases, pressure exerted by the box will be

1. maximum when length and breadth form the base
2. maximum when breadth and width form the base
3. maximum when width and length form the base
4. the same in all the above three cases

Question-49. An apple falls from a tree because of gravitational attractionbetween the Earth and the apple. If F1 is the magnitude of force exerted by the Earth on the apple and F2 is the magnitude of force exerted by the apple on the Earth, then

1. F1 is very much greater than F2
2. F2 is very much greater than F1
3. F1 is only a little greater than F2
4. F1 and F1 are equal

Question-50. An object weighs 10 N in air. When immersed fully in water, it weighs only 8 N. The weight of the liquid displaced by the object will be

1. 2 N
2. 8 N
3. 10 N
4. 12 N

Question-51. If the gravitational attraction of the Earth suddenly disappears, which of the following statements will be true?

1. The weight of body will become zero but the mass will remain same.
2. The weight of a body will remain same but the mass will become zero.
3. Both mass and weight become zero.
4. Neither mass nor weight becomes zero.

Question-52. In the relation F = GM mld2, the quantity G

1. depends on the value ofg at the place of observation
2. is used only when the Earth is one of the two masses
3. is greatest at the surface of the Earth
4. is universal constant of nature

Question-53. Law of gravitation gives the gravitational force between

1. the Earth and a point mass only
2. the Earth and Sun only
3. any two bodies having some mass
4. two charged bodies only

Question-54. The acceleration due to gravity on the Earth depends upon the

1. mass of the body
2. mass of the Earth
3. shape and size of the body
4. volume of the body

Question-55. The atmosphere is held to the Earth by

1. gravity
2. wind
3. clouds
4. Earth?s magnetic field

Question-56. The force of attraction between two unit point masses separated by a unit distance is called

1. gravitational potential
2. acceleration due to gravity
3. gravitational field
4. universal gravitational constant

Question-57. The gravitational force between two objects is F. If masses of both objects are halved without changing the distance between them, then the gravitational force would become

1. F/4
2. F/2
3. F
4. 2F

Question-58. The SI unit of pressure is

1. Nm2
2. N/m
3. N/m2
4. N2/m2

Question-59. The unit of G in the S.I. system is

1. Newton m2/kg2
2. Newton m2 kg2
3. Newton m kg
4. Newton m2/kg

Question-60. The value of acceleration due to gravity

1. is same on equator and poles
2. is least on poles
3. is least on equator
4. increases from pole to equator

Question-61. The value of quantity G in the law of gravitation

1. depends on mass of Earth only
2. depends on radius of Earth only
3. depends on both mass and radius of Earth
4. is independent of mass and radius of the Earth

Question-62. Two objects of different masses falling freely near the surface of the moon would

1. have same velocities at any instant
2. have different acceleration
3. experience forces of same magnitude
4. undergo a change in their inertia

Question-63. When a mango falls from a mango tree then

1. only the Earth attracts the mango.
2. only the mango attracts the Earth.
3. both the mango and the Earth attract each other.
4. both the mango and the Earth repel each other.

Question-64. When a ship floats in sea water

1. The weight of water displaced is greater than the weight of ship
2. The weight of water displaced is less than the weight of the ship
3. The weight of water displaced is equal to the weight of the ship
4. It displaces no water.

Question-65. A ball weighing 4 kg of density 4000 kgm-3 is completely immersed in water of density103 kgm-3. What will be the buoyant force acting on it?

1. 100 N
2. 10 N
3. 1600N
4. 16 N