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⚛️ Physics  ·  Thermodynamics  ·  NEET & JEE

For Van der Waals gas (a, b are constants): (P + an<sup>2</sup>/V<sup>2</sup>)(V - nb) = nRT. At high pressure compared to ideal gas, the gas:

Answer: Is less compressible (harder to compress).

  • A Is less compressible (harder to compress)
  • B Is more compressible than an ideal gas at the same pressure
  • C Behaves identically to an ideal gas under any pressure
  • D Becomes more or less compressible only depending on temperature, not pressure

Correct answer: A. Is less compressible (harder to compress)

Explanation: At high pressures, the (V-nb) term dominates. The effective volume is reduced by b (molecular volume), making it less compressible.

Carnot Cycle (P-V Diagram)VP1→2: isothermal expansion (T_H)2→3: adiabatic expansion3→4: isothermal compression (T_C)4→1: adiabatic compression1234Net work done by the gas = area enclosed by the loop 1→2→3→4→1

The Carnot cycle alternates two isothermal steps (heat absorbed at TH, released at TC) with two adiabatic steps (no heat exchange); the enclosed loop area equals the net work output, and η = 1−TC/TH is the maximum possible efficiency between those two temperatures.

Concept context

Laws of thermodynamics, heat engines, entropy, and gas processes.

Read the full Thermodynamics notes →