CBSE Class 9 Science Gravitation MCQs Set A

Question: The mass of an object is
(a) The amount of matter contained in the object, independent of where that object is found
(b) the force of gravity on that object located at a particular point in space
(c) dependent on whether the object is on the Earth or elsewhere.
(d) divided by the Earth acceleration due to gravity to equal force.

Answer: A

Question: Which of the following was NOT a contribution of Newtons to science?
(a) the first good experimental measure of G, the gravitational constant of proportionality
(b) the law of universal gravitation
(c) F = ma
(d) explanations of optical phenomena

Answer: A

Question: If the distance between objects increases, then the gravitational force between the objects will:
(a) remain same
(b) none of these
(c) decrease
(d) Increase

Answer: C

Question: The relation between the weight of an object on the moon (WM) and on the earth (WE)
(a) WM =6 WE
(b) We = 1/6WM
(c) WM= We
(d) WM =1/6 (We)

Answer: D

Question: The weight of an object is:
(a) lesser on earth and greater on moon
(b) Equal on both earth and moon
(c) Greater on earth and lesser on moon
(d) none of these

Answer: C

Question: The upward force exerted by the liquid displaced by the body when it is placed inside the liquid is called
(a) Buoyant force
(b) Gravitational force
(c) Centripetal force
(d) Force of gravitation

Answer: A

Question: SI Unit of pressure is
(a) Pascal
(b) Newton
(c) m/s
(d) Dyne

Answer: A

Question: The force acting on an object perpendicular to the surface is called
(a) weight
(b) Pressure
(c) Weight
(d) thrust

Answer: D

Question: The expression for finding the gravitational force of attraction between any two bodies is
(a) F= G m1m2/r3
(b) F= G m1m2/r
(c) F= Gm1 m2/r2
(d) F = Gm1/r

Answer: C

Question: The force which keeps the body to move in circular motion when accelerated is
(a) Force of gravitation
(b) Magnetic force
(c) Centripetal force
(d) Electrostatic force

Answer: C

Question: The time of ascent when measured from the point of projection of a body projected upwards , the
(a) Time of ascent=Time of descent
(b) Time of ascent > Time of descent
(c) Time of ascent < Time of descent
(d) All of the above

Answer: A

Question: Weight of an object on the surface of the moon is
(a) 1/6 that on the surface of the earth
(b) 1/5 th that on the surface of the earth
(c) 1/3 that on the surface of the earth
(d) 1/2 that on the surface of the earth

Answer: A

Question: The value of acceleration due to gravity at the poles
(a) zero
(b) Same as at the equator
(c) Is less than at the equator
(d) Is more than at the equator

Answer: D

Question: The value of acceleration due to gravity at the highest point of the motion of the body when a body is projected upwards
(a) 9.8 m/s2 downwards
(b) 0 m/s2
(c) 6 m/s2
(d) 9.8 m/s2 upwards

Answer: A

Question: The value of acceleration due to gravity of the surface of the earth is
(a) 9.8 m/s2
(b) 6 m/s2
(c) 8 m/s2
(d) 4.9 m/s2

Answer: A

Question. A body of mass 1kg is attracted by the earth with a force which is equal to
(a) 9.8N
(b) 6.67x 10¹¹
(c) 1 N
(d) 9.8m/s

Answer :   A

Question. The SI unit of pressure is
(a) Nm²
(b) N/m
(c) N/m²
(d) N2/m²

Answer :   C

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

Answer :   A

Question. Choose the correct unit for the relative density among the following:
(a) kg/cm
(b) unitless
(c) kg/cm
(d) kg/m3

Answer :   B

Question. The gravitational force causes
(a) Tides
(b) Motion of moon
(c) None of them
(d) Both a n b

Answer :   D

Question. 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
(a) maximum when length and breadth form the base
(b) maximum when breadth and width form the base
(c) maximum when width and length form the base
(d) the same in all the above three cases

Answer :   B

Question. The Earth attracts the moon with a gravitational force of 1020N. The moon attracts the earth with a gravitational force of
(a) Less than 1020N
(b) 1020N
(c) Greater than 1020N
(d) 10-20N

Answer :   C

Question. The gravitational force between two bodies does not depend on
(a) their separation
(b) their masses
(c) the product of their masses
(d) the medium between the two bodies

Answer :   D

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

Answer :   C

Question. In the relation F = GM mld2, the quantity G
(a) depends on the value ofg at the place of observation
(b) is used only when the Earth is one of the two masses
(c) is greatest at the surface of the Earth
(d) is universal constant of nature

Answer :   D

Question. 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
(a) equal for all cases
(b) 20cm x 10 cm
(c) 40cm x 10cm
(d) 40cm x 20cm

Answer :   B

Question. When a body is weighed in a liquid, the loss in weight is equal to
(a) weight of liquid displaced by the body
(b) weight of water displaced by the body
(c) weight of body in air
(d) half the weight of body in air

Answer :    A

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

Answer :   D

Question. The atmosphere is held to the Earth by
(a) gravity
(b) wind
(c) clouds
(d) Earth’s magnetic field

Answer :   A