Question

Air enters the compressor at 100 kPa and 25°C having the volume of 1.8 m3/kg and compressed to 5 bar isothermally. The change in internal energy during the process is

• A. 0 kJ
• B. 37 kJ
• C. 1 kJ
• D. 73 kJ

Hint:

In isothermal processes, temperature remains constant, and hence the change in internal energy of an ideal gas is zero.

Answer 1

The Correct Option is A

For an isothermal process, the change in internal energy is zero because the temperature remains constant and internal energy for an ideal gas depends only on temperature. Thus, the change in internal energy during the isothermal compression process is \( \Delta U = 0 \, \text{kJ} \).