250+ TOP MCQs on Thermodynamics – Reversible and Irreversible Processes | Class 11 Physics

Physics Multiple Choice Questions on “Thermodynamics – Reversible and Irreversible Processes”.

1. A cyclic process is always reversible. True or False?
a) True
b) False
Answer: b
Clarification: A cyclic process is one in which the initial and final state is the same. The path need not be retraceable as in the case of a reversible process. For eg: a process could go from A to B And then back to A, but via a different path.

2. What is a quasi-static process?
a) Irreversible
b) Reversible
c) In equilibrium at every state
d) Not involving friction
Answer: c
Clarification: A quasi static process is one in which each stage is in equilibrium with its surroundings. There may be a process which may be quasi static and also involve heat transfer with surrounding and will therefore be irreversible. A process may not involve friction and be a free expansion of gas and therefore can’t be quasi static.

3. What is the relation between work obtained in an reversible and irreversible process?
a) W_rev > W_irr
b) W_rev < W_irr
c) W_rev = W_irr
d) It depends on change in temperature
Answer: a
Clarification: A process is irreversible due to dissipative forces or free expansion or explosive chemical reactions and so on. This causes it to lose the amount of useful work that can be done in an irreversible process. This is not the case for a reversible process. Hence, W_rev > W_irr.

4. Which of the following is an example of reversible process?
a) Wood to ashes
b) Burning of matchstick
c) Making roti from wheat flour
d) Frictionless to and fro motion
Answer: d
Clarification: In frictionless to and fro motion, no form of energy is lost so the path followed from one point to another can be exactly retraced. While the other three are chemical changes and cannot be reversed.