CBSE Class 12 Physics Gravitation MCQs

Answer : (A → s), (B → p), (C → q), (D → r)

Answer : (A → s), (B → p), (C → q), (D → r)

Answer : (A → t), (B → r, s), (C → p, q) (D → r, s)

Answer : (A → q, s), (B → p,t), (C → q, s), (D → r)

MARK THE STATEMENT TRUE OR FALSE :

Question. The force of attraction between two bodies is called gravity.
Answer : False

Question. The value of G depends upon the mass of two objects.
Answer : True

Question. If a spring balance, holding a heavy object is released, it will read zero weight.
Answer : True

Question. The value of G is high if the radius of the body is more and less if radius is less.
Answer : True

Question. The centre of mass and centre of gravity for a small body lie at the same point.
Answer : True

Question. The gravitational force between two bodies changes if a material body is placed between them.
Answer : False

Question. The acceleration of a body thrown up is numerically the same as the acceleration of a downward falling body but opposite is sign.
Answer : True

Question. The value of g is zero at the centre of the earth.
Answer : True

Question. The inertia of an object depends upon its mass.
Answer : True

Question. All objects attract each other along the line joining their centre of mass.
Answer : True

Question. Acceleration due to gravity, g = 2 GMR , where symbols have their usual meanings.
Answer : True

Question. Relative density has no unit.
Answer : True

Question. Archimedes' principle does not apply to gases.
Answer : False

Question. Any solid will sink in water if its relative density is less than unity.
Answer : False

FILL IN THE BLANKS :

Question. .................... is the force of attraction between any two bodies in the universe.
Answer : gravitation

Question. .................... is the force of attraction between a body and a planet.
Answer : gravity

Question. Acceleration due to gravity .................... with height from the surface of the earth.
Answer :decreases

Question. Acceleration due to gravity .................... with depth from the surface of the earth.
Answer : decreases

Question. Acceleration due to gravity is a maximum at the ....................
Answer : poles

Question. .................... of a body changes from place to place but its .................... remains constant.
Answer : weight, mass

Question. The upward force experienced by a body immersed partially or fully in a fluid is called ....................
Answer : buoyant force

Question. Density of a substance is defined as the ratio of the mass of a body to its ....................
Answer : volume

Question. Relative density of a substance is defined as the ratio of the density of the substance to the density of water at ....................
Answer : 4°C

Question. In cgs the relative density of a substance is .................... equal to its density in gcm–3.
Answer : numerically

Question. The combined weight of the sinker and cork is .................... than the weight of the sinker alone.
Answer : less

Question. For a body to float the density of the floating object should be .................... than or equal to the density of the liquid in which it is to float.
Answer : less

Question. The centre of .................... is a point, where the total upthrust, due to fluid displaced by part .................... of body acts.
Answer : buoyancy, the immersed

Question. A fish .................... by squeezing out air, from its ....................
Answer : dives, floating tube

Question. When a body is partly or wholly immersed in a .................... , it experience an ....................
Answer : fluid, upthrust

Question. An iceberg floats with .................... of its volume below ....................
Answer : 11/12, water

Question. The unit of upthrust in SI is ....................
Answer : Newton

Question. Lactometer is used to measure ................... of ....................
Answer : purity, milk

Question. A hydrometer sinks .................... in water than in pure milk.
Answer : more

Question. The density of hot air is .................... that of cold air.
Answer : less than