There is an expansion of a gas in a thermodynamic system. But this change cannot be plotted on a P-V diagram. Then it is (a) an isothermal expansion. (b) a free expansion (c) an adiabatic expansion (d) an isobaric expansion

Answer: (b). Isothermal, adiabatic and isobaric expansions (quasi-static) pass through equilibrium states and can be plotted. Free expansion is instantaneous; intermediate states have no definite P, V, so it cannot be plotted. So the answer is (b) a free expansion.

There is an expansion of a gas in a thermodynamic system. But this… | MHT CET 2026 (19 May, Shift 1)

Q6MHT CET 2026 · 19 MAY · SHIFT 1Easy

P-V Diagrams & Cyclic Processes

There is an expansion of a gas in a thermodynamic system. But this change cannot be plotted on a P-V diagram. Then it is

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Answer: (b)

Isothermal, adiabatic and isobaric expansions (quasi-static) pass through equilibrium states and can be plotted.
Free expansion is instantaneous; intermediate states have no definite $P$ , $V$ , so it cannot be plotted.
So the answer is (b) a free expansion.

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