Physics Thermodynamics PMDC 2020
PMDC Verified Question 45 of 54
In which process the entire of heat supplied to the gas is converted to the internal energy of the gas?
A
Adiabatic process
B
Isobaric process
C
Isothermal process
D
Isochoric process
Tap any option to test your recall and reveal the step-by-step Propolis autopsy.

Propolis Cognitive Error Autopsy

Official Correct Choice:
Option D: Isochoric process
1. Concept:

If a gas is heated in a rigid container, its volume cannot change. Since work done is pressure multiplied by the change in volume, zero volume change means zero work done.

2. Formula:

$$Q = \Delta U + W$$

3. Solution:

  • In an isochoric process, volume is constant (\(\Delta V = 0\)).


  • Work done \(W = P \Delta V = 0\).


  • Applying the First Law of Thermodynamics: \(Q = \Delta U + 0\).


  • Therefore, all heat supplied (\(Q\)) increases the internal energy (\(\Delta U\)).


4. Why other options are incorrect:

In isothermal, all heat converts to work. In isobaric, heat splits into internal energy and work. In adiabatic, no heat is supplied at all.

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