Question

The work done by a gas as it is taken in a cyclic process (shown in graph) is

• A. 2 pv
• B. -2 pv
• C. 3 pv
• D. -3 pv

Hint:

Always check the arrows! Clockwise cycle = Work done by system (+). Anti-clockwise = Work done on system (-).

Answer 1

The Correct Option is B

Step 1: Concept
Work done in a cyclic process is equal to the area enclosed by the cycle on a P-V diagram.

Step 2: Meaning
If the cycle is clockwise, work is positive (by the gas). If it is anti-clockwise, work is negative (on the gas).

Step 3: Analysis
Area of the rectangle $= (\text{Height}) \times (\text{Width}) = (3p - p) \times (2v - v) = 2p \times v = 2pv$.
The process in the graph is anti-clockwise.

Step 4: Conclusion
Total work done $= -2pv$. Final Answer: (B)