Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): The magnitude of work done by an ideal gas during a reversible isothermal expansion is maximum compared to an irreversible expansion between the same volume limits. Reason (R): In a reversible expansion, the external pressure is infinitesimally smaller than the internal pressure of the gas at every

Step-by-step solution

Assertion (A) is correct. The magnitude of work done by a system during expansion is given by the area under the P-V curve. For an isothermal expansion between the same volume limits, the reversible path yields the maximum magnitude of work. Reason (R) is correct and explains the Assertion. Work done is given by w = - P_ ext dV . To maximize the magnitude of expansion work, the opposing external pressure ( P_ ext ) must be as large as possible. In a reversible expansion, P_ ext is kept infinitesimally smaller than