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LOYOLA COLLEGE (AUTONOMOUS), CHENNAI 600 034
B.Sc.DEGREE EXAMINATION -PHYSICS
FIFTH SEMESTER APRIL 2018
PH 5510- QUANTUM MECHANICS
Date: 27-04-2018 Dept. No. Max. 100 Marks
Time: 09:00-12:00
PART A (10X 2 20 marks)
Answer ALL questions
1. Determine the de Broglie wavelength of an electron of energy 1eV.
2. State Heisenberg's uncertainty principle.
3. Define Hermitian operator.
4. Write the time dependent form of Schrodinger's equation.
5. What are eigen functions and eigen values of the operator
x
i



6. Evaluate x y L L .
7. Define inertial and non -inertial frames of reference.
8. A rod 1 m long is moving along its length with a velocity 0.9c.Calculate its length as it
appears to an observer on the earth.
9. State equivalence principle in general relativity.
10. Explain variation of mass with velocity.
PART B x7. 5 30 marks)
Answer any FOUR questions.
11. Explain the distribution of energy in the spectrum of a black body.
12. Obtain the equation for the conservation of probability density.
13. Establish Schrodinger's equation for a linear harmonic oscillator and solve it to
obtain its eigen values and eigen functions..
14. Discuss length contraction and time dilation..
15. Derive Einstein's mass energy relation..
16. Describe Davisson and Germer experiments for the study of electron diffraction..
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PART C 4 x 12.5 50)
Answer any FOUR questions
17. (i)Explain the principle and working of an electron microscope. Outline an
idealised experiment to bring out the significance of Heisenberg's uncertainty
principle.
18. State and prove Ehernfest's theorem
19. Deduce expressions for the Eigen values of the square of the total angular
momentum and its z component.
20. Describe the Michelson- Morley experiment. Explain the physical significance of
negative results.
21. What is general theory of relativity? Discuss the important conclusions derived
from it. Explain gravitational red shift.
22. With necessary theory explain alpha decay quantum mechanically.