Question

A system undergoes one clockwise cycle from point X back to point X as shown in the figure below:

The correct statement about this process is

• A. Internal energy of the system decreases at the end of the cycle
• B. Entropy of the system increases at the end of the cycle
• C. System performs work on the surroundings during the cycle.
• D. Heat exchanged between system and surroundings is zero during the cycle.

Answer 1

The Correct Option is C

In the given cyclic process, the system undergoes a clockwise cycle, indicating that work is being done by the system on the surroundings. During a clockwise cycle on a Pressure-Volume (P-V) diagram, the system expands (increasing volume), which corresponds to the system performing work on the surroundings.

• (A) is false because in a cyclic process, the internal energy of the system remains the same after one complete cycle.
• (B) is false because the total entropy change of the system is zero in a reversible cyclic process.
• (C) is true. The system performs positive work on the surroundings as it expands.
• (D) is false because there is heat exchange between the system and surroundings during a non-adiabatic process.