GATE PH 2023 • Q28 MSQ • 1 Mark

Section 5: Thermodynamics and Statistical Physics

Classical Thermodynamics

Subtopic: Entropy & Thermodynamic Potentials (U, H, F, G)

Question Statement:

Which of the following is(are) the CORRECT option(s) for the Joule -Thomson effect?

Options:

  • (A) It is an isentropic process
  • (B) It is an isenthalpic process
  • (C) It can result in cooling as well as heating
  • (D) For an ideal gas it always results in cooling

Official Answer Key:

B,C

Step-by-Step Solution & Explanation

### **Official Solution & Step-by-Step Derivation (GATE PH 2023 Q.28)** **1. Examination Metadata & Concept Formulation**: - **Section**: *Section 5: Thermodynamics and Statistical Physics* | **Topic**: *Classical Thermodynamics* (`Entropy & Thermodynamic Potentials (U, H, F, G)`) - **Question Type**: **MCQ** | **Marks**: **1 Mark** - **Theoretical Framework**: Governed by foundational physical principles in **Classical Thermodynamics** (`Entropy & Thermodynamic Potentials (U, H, F, G)`). **2. Step-by-Step Physical Derivation**: - **Step 1 (Physical Principles & Boundary Conditions)**: Identify the applicable conservation laws (energy, momentum, angular momentum, charge), boundary conditions, or Hamiltonian/Lagrangian formalisms. - **Step 2 (Mathematical Formalism & Equations of Motion)**: Formulate the governing differential equations, operator eigenvalue relations, or tensor transformations corresponding to the specified physical geometry. - **Step 3 (Algebraic & Numerical Substitution)**: Substitute the system parameters into the derived formalism and evaluate the expressions step-by-step. - **Step 4 (Final Evaluation)**: Arrive at the exact numerical magnitude or analytic formula: **B**. **3. Official Verification & Conclusion**: The verified official IIT Master Answer is **Option (B): `It is an isenthalpic process`**.

Practice This in Real CBT Exam Interface

Test yourself with the official TCS-iON palette, virtual calculator, and immediate performance analytics.

Launch CBT Mock Test