Question

In thermodynamic processes, which of the following statements is NOT true?

• A. In an isothermal process, the temperature remains constant.
• B. In an adiabatic process, the system is insulated from surroundings.
• C. In an isochoric process, pressure remains constant.
• D. In an adiabatic process, $PV^{\gamma}=$ constant.

Hint:

Isochoric = Constant Volume; Isobaric = Constant Pressure.

Answer 1

The Correct Option is C

Step 1: Understanding the Question:
We need to identify the incorrect definition of common thermodynamic processes.

Step 2: Detailed Explanation:
- (A) Isothermal process: By definition, the temperature \( T \) of the system remains constant throughout. This is true.
- (B) Adiabatic process: This process occurs without any heat exchange (\( dQ = 0 \)) between the system and surroundings, usually achieved by insulation or speed. This is true.
- (C) Isochoric process: By definition, the volume (\( V \)) remains constant. The process where pressure remains constant is called an isobaric process. Therefore, statement (C) is false.
- (D) Adiabatic process: For an ideal gas undergoing a reversible adiabatic process, the relation \( PV^\gamma = \text{constant} \) holds. This is true.

Step 4: Final Answer:
Statement (C) is not true.