Physics Thermodynamics SZABMU 2024
PMDC Verified Question 5 of 54
In an isothermal condition of any thermodynamic system, the change in internal energy:
A
Becomes maximum
B
Remains constant
C
Becomes zero
D
Becomes minimum but greater than zero
Tap any option to test your recall and reveal the step-by-step Propolis autopsy.

Propolis Cognitive Error Autopsy

Official Correct Choice:
Option C: Becomes zero
1. Concept:

The internal energy of an ideal gas is a strict function of its temperature. If the temperature does not change, neither does the internal energy.

2. Formula:

$$\Delta U = n C_v \Delta T$$

3. Solution:

  • An isothermal condition mandates that temperature remains exactly constant throughout the entire expansion or compression.


  • Therefore, the change in temperature is zero (\(\Delta T = 0\)).


  • Substituting this into the energy formula, the CHANGE in internal energy \(\Delta U\) becomes mathematically exactly zero.


4. Why other options are incorrect:

While the total absolute internal energy \(U\) remains constant, the question specifically asks for the change in internal energy (\(\Delta U\)), which is strictly zero.

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