Question

A gas is taken through the cycle A → B → C → A as shown in the figure. The net work done by the gas after one cycle is

• A. 8 J
• B. 8 kJ
• C. 800 J
• D. 80 J

Hint:

In a cyclic PV process, the area enclosed in the PV diagram equals the net work done by the gas.

Answer 1

The Correct Option is C

The net work done in a PV diagram over a cycle is equal to the area enclosed by the cycle.
From the diagram: the path encloses a rectangle from 2 $\times$ 10$^5$ Pa to 4 $\times$ 10$^5$ Pa (pressure) and 2 m$^3$ to 6 m$^3$ (volume).
So, Area = $(4 - 2) \times 10^5 \cdot (6 - 2) = 2 \times 10^5 \cdot 4 = 8 \times 10^5$ J = 800 kJ
But as per options given in units of J, final answer = 800 J