PH3256 Physics for Information Science Important Questions

PH3256 Physics for Information Science

Important Questions

Unit 1 Part B

1. What are the postulates of free electron theory? Derive an expression for electrical conductivity based on free electron theory.
2. What is meant by effective mass of an electron? Derive an expression for the effective mass of an electron?
3. Write a short note on Fermi dirac distribution.
4. Derive an expression for energy eigen value and eigen function for a particle moving in the potential V(x)=0 for 0<x<a and V(x)=∞ for 0>x>a.
5. Extend the above eigen value and eigen function for a particle in three dimensional rectangular box and discuss the degenerate states of the particle.
6. Derive an expression for the density of states.
7. Describe the classical free electron theory to obtain an expression for electrical and thermal conductivity and deduce Lorentz number.

Unit 2 Part B

1. Derive an expression for density of electrons in the conduction band of an N-type and density of holes in the valence of P-type extrinsic semiconductor.
2. Derive an expression for Hall coefficient and describe the experimental setup for the measurement of Hall coefficient.
3. Derive an expression of electron concentration in the conduction band of an n-type extrinsic semiconductor.
4. Explain with a neat sketch, the variation of Fermi level with temperature in an n-type semiconductor.
5. Explain in detail
   (i) Schottky diode
   (ii) Ohmic contacts.
6. Derive an expression for the number of density of holes in an intrinsic semiconductor.
7. Explain direct and indirect bandgap semiconductors.
8. What is a hall effect? Derive an expression for hall coefficient. Describe an experiment for the measurement of the hall coefficient.
9. Find the hall voltage in a Si dopedwith 10²³ phosphor atoms m^-3. The Si sample is 100 µm thick with a current flow of 1 mA for a magnetic field of 10-5 Wb cm

Unit 3 Part B

1. Distinguish between Ferro, antiferro and ferrimagnetism materials. Give some examples for each type.
2. Explain the different contributions for the formation of domains in a ferro magnetic material and show how the hysteresis curve is explained on the basis of the domain theory.
3. Explain the magnetic principle in computer data storage
4. Differentiate between hard and soft magnetic materials.
5. Explain in detail about the domain theory of ferromagnetism.
6. Discuss in detail about the classification of magnetic materials.

Unit 4 Part B

1. Explain with a neat sketch the construction, working and V-I characteristics of solar cell.
2. Mention the applications of solar cells.
3. Explain with a neat sketch the basic principle, working and the advantage of LED.
4. Calculate the wavelength of light emitted by an LED with band gap of energy 1.8 eV.
5. Explain carrier generation and recombination in semiconductor.
6. Describe the construction and working of a photo diode.
7. Describe the construction and working of a solar cell.
8. Explain the absorption and emission of light in metal, insulator and semiconductor.
9. Describe the construction and working of a LED with energy band diagram.

Unit 5 Part B

• Explain Quantum confinement in quantum wells, wires and dots.
• Explain the principle and working of single electron transistor.
• Explain the importance of quantum system for information processing.
• Explain the advantage of quantum computing over classical computing.
• Explain quantum confinement and quantum structures in nano materials.
• Explain in detail about Bloch sphere.
• Distinguish between Classical and quantum computing.
• Explain coulomb blockade effect and single electron phenomena.