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MHT CET202526 Apr 2025Morning ShiftPhysicsThermodynamicsActual

In case of free expansion, which one of the following statements is WRONG ?

Options

  1. AIt is an instantaneous change.
  2. BThe system is not in thermodynamic equilibrium.
  3. CFree expansion can be plotted on a p-V diagram.
  4. DIt is an uncontrolled change.

Correct answer

C. Free expansion can be plotted on a p-V diagram.

Step-by-step solution

Free expansion occurs when a gas expands into a vacuum. The process is rapid and effectively instantaneous, with no external resistance. The system exhibits significant pressure and density gradients during expansion, placing it far from thermodynamic equilibrium. Since free expansion is a non-equilibrium process, intermediate states lack well-defined pressure and volume values. A p - V diagram requires equilibrium states to plot a continuous path; only initial and final states can be represented. This makes the cl

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