Assertion : During an adiabatic process, heat energy is not exchanged between system and its surroundings.
Reason : The temperature of a gas increases when it undergoes andn adiabatic expansion.

Options

A. If both the assertion and reason are true and reason is correct explanation of the assertion .
B. If both the assertion and reason are true but reason is not a correct explanation of the assertion .
C. If the assertion is true but the reason is false.
D. If both assertion and reason are false.

Answer

C

Explanation

In adiabatic process, no heat enters or leaves the system. The sytem is completely insulated from its surrounding. From first law of thermodynamics , change in internal energy .
`DeltaE=1-W=0-W=-W` .
Since the work is done at the expense of internal energy , therefore internal energy of the system decreases and hence temperature of the gas falls.