M.Sc DEGREE EXAMINATION, FEBRUARY 2018.
Fourth Semester
Physics
Paper QUANTUM MECHANICS II
(Non CBCS Old Regulation)
2 20741
Time 3 Hours Max. Marks 100
PART — A
(Short Answer Type)
Answer any FIVE of the following. 8 40 Marks)
1. Write a note on symmetric and anti- symmetric wave functions.
2. Explain the concept of ortho and para hydrogen.
3. Briefly explain the variation technique.
4. Write a note on sudden and adiabatic perturbations.
5. Discuss the zero energy scattering.
6. Explain the validity of born approximation.
7. Write a note on Dirac matrices.
8. Explain the theory of holes.
PART — B
(Essay Answer Type)
Answer ALL questions. 15 60 Marks)
9. Explain the indistinguishability of identical particles and explain the Pauli's
exclusion principle.
Or
Explain in detail the oscillations and rotations of hydrogen molecule using
Heitler -London method.

10. Explain the time -independent perturbation method and discuss the effect of
anharmonicity on the solution of harmonic oscillator problem.
Or
Discuss the WKB approximation and explain the alpha particle decay.
11. Discuss in detail the method of partial waves for the analysis of elastic
scattering.
Or
Discuss the scattering by a central potential and square -well potential.
12. Derive Klein Gordon equation. Obtain the continuity equation in Klein
Gordon theory. Mention the major drawbacks of this theory.
Or
Obtain solutions for a free particles based on Dirac's relativistic equation.
Explain the concept of negative energy states.
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