Question

At T(K), the following graph is obtained for an ideal gas.

Which of the following graphs correctly represents the work done on the gas (shaded part)?

• A.

  

• B.

  

• C.

  

• D.

  

Hint:

In a PV diagram, the area under the curve represents work done.
- If volume increases, the gas does work (positive work).
- If volume decreases, work is done on the gas (negative work).

Answer 1

The Correct Option is B

Step 1: Understanding Work Done in a PV Diagram 
- Work done by or on a gas is given by the area under the PV curve. 
- For an expansion process, work is done by the gas and is positive. 
- For a compression process, work is done on the gas and is negative. 

Step 2: Identifying the Correct Graph 
- The given graph represents a process where pressure \( P \) decreases as volume \( V \) increases. 
- The shaded area under the curve represents the work done on or by the gas. 
- Among the given options, Option (2) correctly represents the work done, as the shading is correctly placed under the curve. Thus, the correct answer is \( \mathbf{(2)} \).