Interpret the cyclic process on the graph

In a cyclic process on a $P$-$V$ diagram, the work done by the gas is equal to the area enclosed by the cycle.

Identify the path $C \to A \to B$

From the figure, the cycle $CAB$ forms a triangular region on the $P$-$V$ diagram.

The work done in one cycle is: $W = \text{Area enclosed by triangle}$

Use triangle area formula

$W = \frac{1}{2} \times (\text{base}) \times (\text{height})$

From the graph, the horizontal difference in volume is: $\Delta V = 2\,\text{m}^3$

and the vertical difference in pressure is: $\Delta P = 10\,\text{N/m}^2$

Therefore, $W = \frac{1}{2} \times 2 \times 10 = 10\,\text{J}$

Final answer

$\boxed{10\,\text{J}}$

Compare with stored correct answer

Stored correct answer is B.

Our derived answer is also 10 J, i.e. option B.