Question

A gas undergoes change in its state from state A to state B, via three different paths as shown in the figure. Select the correct alternative(s)

• A. Change in internal energy in all the three paths is equal
• B. In all the three paths heat is absorbed by the gas
• C. Heat absorbed / released by the gas is maximum in path (1)
• D. Temperature of the gas first increases and then decreases continuously in path (1)

Answer 1

Answer: (A), (B), (C)

The correct options are
A Change in internal energy in all the three paths is equal
B In all the three paths heat is absorbed by the gas
C Heat absorbed / released by the gas is maximum in path (1)

Internal energy depends only on initial and final states.since initial and final states for the three processes are the same. Change in internal energy in all the three processes are the same. Hence, option A is correct.

In each path, we can see that area under P-V diagram is positive. By first law, heat is absorbed by the gas in all the three processes. Hence,option B is correct.

Since area under P-V diagram for process 1 is high and since change in internal energy is same for all. By first law, the heat absorbed/released by gas is maximum in path(1). Hence, option C is correct.

In path 1, we cannot determine the temperature without knowing the values of heat absorbed and work done.