# Physics Top MCQs – 3

Intensity of sound at a point is __________ its distance from the source.
(A) Directly proportional to
(B) Inversely proportional to
(C) Directly proportional to square of
(D) Inversely proportional to square of

Out of the following pairs, which one does not have identical dimension?
(A) Moment of inertia and moment of a force
(B) Work and Torque
(C) Angular momentum and Planck’s constant
(D) Impulse and Momentum

On a stationary sail boat, air is blown from a fan attached to the boat. The boat
(A) Moves in opposite direction in which the air is blown
(B) Does not move
(C) Moves in the same direction in which air blows
(D) Spins around

Isotopes of an element contain
(A) The same number of protons but different number of neutrons
(B) The same number of neutrons but different number of protons
(C) Equal number of protons and electrons
(D) Equal number of nucleons

Identify the vector quantity from the following
(A) Heat
(B) Angular momentum
(C) Time
(D) Work

An aeroplane is flying horizontally with a velocity of 600 km/h and at a height of 1960 m. When it is vertically at a point A on the ground a bomb is released from it. The bomb strikes the ground at point B. The distance AB is
(A) 1200 m
(B) 0.33 km
(C) 3.33 km
(D) 33 km

Photosynthesis takes place faster in
(A) Yellow light
(B) White light
(C) Red light
(D) Darkness

It is more difficult to walk on a sandy road than on a concrete road because
(A) Sand is soft and concreter is hard
(B) The friction between sand and feet is less than that between concrete and feet
(C) The friction between sand and feet is more than that between concrete and feet
(D) The sand is grainy but concrete is smooth

Radiocarbon is produced in the atmosphere as a result of
(A) Collision between fast neutrons and nitrogen nuclei present in the atmosphere
(B) Action of ultraviolet light from the sun on atmospheric oxygen
(C) Action of solar radiations particularly cosmic rays on carbon dioxide present in the atmosphere
(D) Lightning discharge in atmosphere