LOYOLA COLLEGE (AUTONOMOUS), CHENNAI – 600 034
M.Sc. DEGREE EXAMINATION – PHYSICS
FOURTH SEMESTER – APRIL 2012
PH 4806 – SOLID STATE PHYSICS – II
Date : 16-04-2012 Dept. No. Max. : 100 Marks
Time : 1:00 – 4:00
PART – A
Answer ALL questions: (10×2=20)
- What are direct and indirect band semiconductors ?
- Show that n0 p0 is independent of the position of the Fermi level.
- Establish the relation between relative permeability and magnetic susceptibility.
- Evaluate Lande’s g factor for S=0.
- What is pyroelectric effect?
- What is photoconductivity?
- Explain ferri-electricity.
- What is the working principle of a Maser?
- Mention the three critical parameters of a super conductor.
- Explain isotope effect in superconductivity.
PART – B
Answer any FOUR questions: (4×7.5 = 30)
- Explain the effect of temperature on the mobility of charge carriers in a semiconductor.
- Give the classical theory of electronic polarisation.
- Explain the phenomenon of absorption in semiconductors and the role of excitons.
- Derive an expression for anti ferro magnetic susceptibility.
- Write a short note on high temperature superconductivity.
PART – C
Answer any FOUR questions : (4×12.5 =50)
- (a) Explain with suitable energy level diagrams the rectifying effect at a metal semiconductor junction. (8.5)
(b). Calculate the intrinsic conductivity σi at 300K for germanium. Given μe and μp are 0.39 and 0.19 m2v-1s-1 , Eg is 0.72eV and C is 4.8 x10 21 (4)
- (a) Derive an expression for the local field in a dielectric.
(b) Establish the Clausius-Mossotti equation. (5)
18 . (a) Explain the phenomenon of photoluminiscence. (5)
(b) Derive expressions for Einstein coefficients of stimulated emission.
- (a) Explain classical theory of dia-magnetism.
(b) What are ferrites? Give any two examples. (4)
- Briefly outline the BCS theory of superconductivity and derive an approximate expression for the transition temperature.
Latest Govt Job & Exam Updates: