What is photovoltaic effect. Explain construction and working of solar cell.
[7 marks]Give assumptions of classical free electron theory.
[3 marks]Explain mechanism of superconductivity.
[4 marks]Explain properties of superconductors.
[7 marks]Give difference between Ntype and Ptype semiconductors.
[3 marks]Derive an expression for joint density of states.
[4 marks]Explain Kronig Penney model in detail.
What are hot probe method.
[3 marks]Explain fermi levels.
[4 marks]Explain classification of materials as conductors, insulators and semiconductors.
[7 marks]Give difference between intrinsic and extrinsic semiconductors.
[3 marks]Explain drift and diffusion current.
[4 marks]Explain direct and indirect band gap with E-k diagrams.
[7 marks]Define superconductivity and critical temperature.
[3 marks]Discuss fermi golden rule.
[4 marks]Explain diffusion mechanism in detail.
[7 marks]Define radiative and non-radiative transitions.
[3 marks]Explain emission and absorption.
[4 marks]Explain experimental procedure for DLTS.
[7 marks]The critical temperature of Nb is 9.15 K. At zero kelvin, the critical field is 0.196 T. Calculate the critical field at 6 K.
[3 marks]Explain Drude model.
[4 marks]Why two probe method for resistivity measurement failed and hence explain four probe method.
[7 marks]Give success and drawback of classical free electron theory.
[3 marks]Derive expression of electron concentration in conduction band.
[4 marks]Discuss UV – VIS method for band gap measurement of semiconductors.
[7 marks]