Elasticity — JEE physics STD 12 Science — Question

Assertion : Transverse waves are not produced in liquids and gases.
Reason : light waves are transverse waves.

Assertion : Reversible systems are difficult to find in real world.
Reason : Most processes are dissipative in nature

Assertion : A light body and heavy body have same momentum. Then they also have same kinetic energy.
Reason : Kinetic energy does not depend on mass of the body.

Assertion : The concept of surface tension is held only for liquids.
Reason : Surface tension does not hold for gases.

Assertion : In everyday life the Doppler's effect is observed readily for sound waves than light waves.
Reason : Velocity of light is greater than that of sound.

Assertion : In the case of free fall of the lift, the man will feel weightlessness.
Reason : In free fall, acceleration of lift is equal to acceleration due to gravity.

Assertion : The earth's magnetic field is due to iron present in its core.
Reason : At a high temperature magnet losses its magnetic property or magnetism.

Assertion : A tuning fork is made of an alloy of steel, nickel and chromium.
Reason : The alloy of steel, nickel and chromium is called elinvar.

Assertion : Efficiency of a Carnot engine increase on reducing the temperature of sink.
Reason : The efficiency of a Carnot engine is defined as ratio of net mechanical work done per cycle by the gas to the amount of heat energy absorbed per cycle from the source.

Assertion : Acceleration is proportional to the displacement. This condition is not sufficient for motion in simple harmonic.
Reason : In simple harmonic motion direction of displacement is also considered.