1. Describe in detail and with the aid of diagrams the Photoelectric Effect experiment. (500 words)

2. Describe the Davisson and Germer Electron Scattering Experiment. (500 words)

3. Describe the excitation of electrons in an intrinsic semiconductor and derive an equation for the conductivity of the material. (500 words)

4. Explain what is meant by the following terms in the context of semiconducting materials: (i) p-type, (ii) n-type, (iii) majority carrier, (iv) minority. (500 words)

5. Explain with the aid of energy band diagrams the flow of current through a p-n junction under (i) zero bias, (ii) reverse bias and (iii) forward bias conditions. (500 words)