CBSE Class 9 Science Gravitation MCQs Set 02

Question. 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:
(a) 1/4 times
(b) 4 times
(c) 1/2 times
(d) Unchanged

Question.The unit of G in the S.I. system is:
(a) Newton m2/kg2
(b) Newton m2 kg2
(c) Newton m kg
(d) Newton m2/kg

Answer:   A

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

Answer:   C

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

Answer:   D

Question. 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______.
(a) mass
(b) density
(c) radius
(d) All of the above

Answer:   D

Question. An object weighing 5 N in air, weighs 4.5 N a liquid. The buoyant force experienced by the object is
(a) (5 + 4.5) N
(b) 4.5/5 N
(c) 5/4.5 N
(d) 0.5 N

Answer:   D

Question. Universal law of gravitation does not explain
(a) the tides on earth due to the moon
(b) the motion of electrons in an atom
(c) the motion of planets around the Sun
(d) the motion of the moon around the earth

Answer:   B

Question. An apple and a stone dropped from certain height accelerates
(a) equally
(b) differently
(c) depending on density
(d) depends on the position of the sun

Answer:   A

Question. An astronaut in the orbit in a spacecraft feels weightlessness
(a) due to the absence of gravity inside
(b) due to the fact that spacecraft has no energy
(c) because acceleration in the orbit is equal to acceleration of gravity outside
(d) there is no gravity outside

Answer:   C

Question. A coin and a feather are dropped together in a vacuum.
(a) The coin will reach the ground first.
(b) The feather will reach the ground first.
(c) Both will reach the ground together.correct
(d) The feather will not fall down.

Answer:   C

Question. The mass of the earth is:
(a) 6.4 × 10²⁴
(b) 6 × 10¹⁰ kg
(c) 6 × 10²⁴ kg
(d) 6 × 10¹⁹ kg

Answer:   C

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

Answer:   D

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

Answer:   A

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 Kgcorrect
(b) 6 Kg
(c) 2 Kg
(d) 72 Kg

Answer:   A

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

Answer:   B

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

Answer:   C

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

Answer:   D

Question. Weight of an object is highest at
(a) Center of earth
(b) Poles
(c) Above the earth’s surface
(d) Equator

Answer:   B

Question. The value of acceleration due to gravity at the Mount
Everest is
(a) g
(b) > g
(c) < g
(d) zero

Answer:   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

Answer:   A

Question. At which of the following locations is the value of g largest?
(a) On top of the Mount Everest
(b) On top of Qutub Minar
(c) At a place on the equator
(d) A camp site in Antarctica

Answer:   D

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 Nwrong
(b) 60 N
(c) 20 Ncorrect
(d) 720 N

Answer:   C

Question. 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:
(a) Same as that on the earth
(b) About one-fifth of that on the earth
(c) About one-sixth of that on the earth
(d) About one-fourth of that on the earth

Answer:   A

Question. 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?
(a) 100 N
(b) 10 N
(c) 1600N
(d) 16 N

Answer:   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

Answer:   C

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

Answer:   C

Question. When a body is thrown up, the force of gravity is
(a) in the upward direction
(b) in the downward direction
(c) zero
(d) in the horizontal direction

Answer:   B

Question. 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?
(a) d1 > d2 > d3
(b) d2 > d3 > d1
(c) d1 < d2 < d3
(d) d3 > d2 > d1

Answer:   C

Question. The constant G
(a) is a very small quantity
(b) is a force
(c) is the same as g
(d) decrease with increasing altitude

Answer:   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

Answer:   A