Theory 1. Give assumptions of classical free electron theory. Give success and drawback of classical free electron theory.

Theory 2. Derive expression of electron concentration in conduction band.

Theory 4. Explain Kronig-Penney model in detail.

Theory 8. Explain fermi levels.

Theory 9. Discuss Fermi golden rule.

Theory 10. Explain Classification of materials as conductors, insulators and semiconductors.

Theory 24. Explain Drude model.

Theory 28. Derive an expression for density of energy states in metals.

Theory 3. Give difference between N type and P type semiconductors.

Theory 11. Explain intrinsic and extrinsic semiconductors with necessary diagram.

Theory 12. What is PN junction diode? What is external bias? Describe its forward and reverse bias conditions with appropriate diagram.

Theory 17. Explain direct and indirect band gap with E-k diagrams.

Theory 26. Write a short note on exciton.

Theory 27. Derive an equation of joint density of states.

Theory 30. Explain construction and working of Schottky junction.

Theory 5. Explain properties of superconductors.

Theory 6. Differentiate between soft and hard superconductors.

Theory 7. Explain BCS theory for superconductivity.

Theory 18. Give formation and applications of SQUID.

Theory 19. Define superconductivity and critical temperature.

Theory 31. Explain London's penetration depth.

Theory 32. Give the difference between type 1 and type 2 superconductor.

Theory 13. What is photovoltaic effect. Explain construction and working of solar cell.

Theory 14. Give applications of solar cell.

Theory 15. Define Hall effect and Hall coefficient. Derive equation to find Hall voltage. What does it signify?

Theory 16. State principle and discuss working of semiconductor laser.

Theory 20. Define radiative and non-radiative transitions.

Theory 21. Explain emission and absorption.

Theory 22. Explain experimental procedure for DLTS.

Theory 23. Discuss the technique to obtain band gap by UV-Vis spectroscopy using absorption or transmission.

Theory 25. Discuss Van Der Pauw method.

Theory 29. Explain four probe method. Derive an equation to calculate resistivity of a thin sample.