Question

2. In an open system, for maximum work, the process must be entirely
(A) irreversible
(B) reversible
(C) c) adiabatic
(D) none of the mentioned​

Answer 1

the correct answer will be B

Reversible

Answer 2

If in a system exchange of both matter and energy occur with the surrounding, such a system is called an open system.

Explanation:

The answer is option B) Reversible.

In thermodynamics, the work is done when the gas expands or contracts against the external pressure.

The general expression of the work done is:-

$w= -P_{ext}(V_2 - V_1)\\w= -P_{ext}(V_f -V_i)$

Reversible work done is the maximum work done. This is because the for reversible expansion, $P_{ext}$ is the maximum possible value of the pressure, because if the value id greater than this no expansion will occur.

Therefore, for a given change of volume, $w_{rev} = w_{max}$.