Question

Which of the following is reversible process?

• A. Production of heat by friction
• B. Joule Thomson effect
• C. Production of heat by passage of current through a resistance
• D. Slow expansion/compression of a gas at constant temperature

Hint:

Slow quasi-static isothermal expansion or compression is a standard example of a reversible process.

Answer 1

The Correct Option is D

Concept:
A reversible process is an ideal process that takes place infinitely slowly and can be reversed without leaving any change in the system and surroundings.

Step 1: Check friction.
Production of heat by friction is irreversible. \[ A \text{ is incorrect} \]

Step 2: Check Joule Thomson effect.
Joule Thomson expansion is a throttling process and is irreversible. \[ B \text{ is incorrect} \]

Step 3: Check current through resistance.
Heat production in resistance is Joule heating and is irreversible. \[ C \text{ is incorrect} \]

Step 4: Check slow isothermal expansion/compression.
A very slow expansion or compression of a gas at constant temperature can be considered reversible. \[ D \text{ is correct} \] \[ \therefore \text{Correct Answer is (D)} \]