Question

Given below are two statements for an adiabatic process involving an ideal gas.

Statement (I) : More cooling of the gas is observed during reversible expansion as compared to irreversible expansion.

Statement (II) : More heating of the gas is observed during reversible compression as compared to irreversible compression.

In the light of the above statements, choose the correct answer from the options given below :

• A. Both Statement (I) and Statement (II) are correct
• B. Statement (I) is correct but Statement (II) is incorrect
• C. Statement (I) is incorrect but Statement (II) is correct
• D. Both Statement (I) and Statement (II) are incorrect

Answer 1

Answer: (A)

Both Statement (I) and Statement (II) are correct

Answer 2

For an adiabatic process, no heat is exchanged with the surroundings. In a reversible process the work done is maximized (either done by or on the system), so:

• During expansion: A reversible expansion does maximum work, hence the drop in internal energy is larger, causing the gas to cool more than in an irreversible expansion.
• During compression: A reversible compression requires maximum work input; therefore, the increase in internal energy (and hence temperature) is greater than that in an irreversible compression.

Thus, both statements are correct.