Question

Assertion Heat absorbed by the gas during an isochoric process goes entirely to change its internal energy and its temperature.
Reason In an isochoric process, volume is constant.

• A. Both Assertion and Reason are correct and Reason is the correct explanation of Assertion.
• B. Both Assertion and Reason are correct but Reason is not the correct explanation of Assertion.
• C. Assertion is correct but Reason is incorrect.
• D. Assertion is incorrect but Reason is correct.

Answer 1

Answer: (A)

In an isochoric process, volume is constant.
So, work done $\Delta W=p\Delta V=0$
Thus, according to first law of thermodynamics,
$\Delta Q=\Delta U+\Delta W$
$\Rightarrow \Delta Q=\Delta U$
Therefore, heat absorbed by the gas goes entirely to change its internal energy and its temperature.
Therefore, Assertion and Reason are correct and Reason is the correct explanation of Assertion.