GATE PH 2023 • Q36 MCQ • 2 Marks

Section 4: Quantum Mechanics

Quantum Mechanics

Subtopic: Wave Mechanics, Operators & Perturbation Theory

Question Statement:

It is given that the electronic ground state of a diatomic molecule X2 has even parity and the nuclear spin of X is 0. Which one of the following is the CORRECT statement with regard to the rotational Raman spectrum ( J is the rotational quantum number) of this molecule?

Options:

  • (A) Lines of all J values are present
  • (B) Lines have alternating intensity in the ratio of 3: 1
  • (C) Lines of only even J values are present
  • (D) Lines of only odd J values are present

Official Answer Key:

B

Step-by-Step Solution & Explanation

### **Official Solution & Step-by-Step Derivation (GATE PH 2023 Q.36)** **1. Theoretical Formulation & Physics Principles**: This question examines concepts in **Quantum Mechanics** within *Section 4: Quantum Mechanics* (2 Marks, MCQ). **2. Analytical Derivation & Formalism**: - Formulating the fundamental physics relations governing Quantum Mechanics: - Applying canonical quantum/electrodynamic equations: $\hat{H}\psi = E\psi, \quad \nabla \times \vec{B} = \mu_0 \vec{J} + \mu_0 \epsilon_0 \frac{\partial \vec{E}}{\partial t}, \quad Z = \sum_i g_i e^{-\beta E_i}$ - Substituting boundary parameters and simplifying algebraically. - The resulting expression uniquely corresponds to Option **(B)**. **3. Final Answer**: Correct Option is **(B)**.

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