Question

Consider the thermodynamic process undergone by a system, shown in the figure. During the process, work done by the system: [$P$ is pressure and $V$ is volume]

• A. Continuously increases
• B. Continuously decreases
• C. First increases then decreases
• D. First decreases then increases.

Answer 1

The correct option is A Continuously increases


We know that work done by the system is given by area under $P-V$ graph.
$W=\int dW=\int P_{0}dV-----\left(1\right)$

When system goes from A to B first pressure decreases and then it increases, but remains greater than zero.
Also, volume continuously increases as system goes from A to B.
Thus, from (1), $W>0$ as $P_0\&dV>0$ (always)
Hence, the work done by the system continuously increases.