Question

The P-V diagram of a Carnot's engine is shown in the graph below. The engine uses 1 mole of an ideal gas as working substance. From the graph, the area enclosed by the P-V diagram is
[ The heat supplied to the gas is 8000 J ]

• A. 2000 J
• B. 3000 J
• C. 1000 J
• D. 1200 J

Answer 1

The Correct Option is B

Given: 

• The engine uses 1 mole of an ideal gas.
• Heat supplied to the gas: \( Q_{in} = 8000 \) J

Step 1: Understanding Work Done

The area enclosed by the P-V diagram represents the work done by the engine:

\[ W = Q_{in} \times \eta \]

For a Carnot engine, efficiency \( \eta \) is given by:

\[ \eta = 1 - \frac{T_C}{T_H} \]

From the problem, we use the given heat supplied and known thermodynamic properties to determine the work done.

Step 2: Calculation

Using the given data:

\[ W = 8000 \times \frac{3}{8} \]

\[ W = 3000 \text{ J} \]

Answer: The correct option is B (3000 J).