Question

From the following \( p-V \) diagram, an ideal gas undergoing a change of state from A to B. Four different processes I, II, III, and IV as shown in the figure may lead to the same change of state. 

• A. Work done is maximum in case I
• B. Change in internal energy is the same in all the four cases
• C. Change in internal energy is the same in III and IV cases, but not in I and II
• D. Work done is minimum in case II

Hint:

For an ideal gas, the change in internal energy depends only on the initial and final states, not on the path taken.

Answer 1

The Correct Option is B

For an ideal gas, the change in internal energy depends only on the change in temperature and not on the path taken. Since the gas undergoes the same change of state from A to B, the change in internal energy is the same in all four processes. This is a fundamental result of the first law of thermodynamics, which states that internal energy is a state function. Therefore, the correct answer is (B).