Anna University Model Question Papers

Anna University Model Question Paper - 1

Answer ALL questions.

PART A (10 x 2 = 20 marks)

1. Distinguish between Mean free path and Collision time.

2. Define density of energy states.

3. What are n-type and p-type semiconductor? Give examples.

4. Distinguish between Ohmic and Schottky contacts.

5. Define the terms intensity of magnetization and flux density.

6. Mention the energies involved in origin of domains in ferromagnetic material.

7. What is recombination process in semiconductors? (d)

8. List out any four advantages of LED in electronic display. 9. Define the term quantum well and quantum wire.

10. What is spintronics?

Part B (5 x 16 = 80 marks)

11. (a) Deduce mathematical expressions for electrical conductivity and thermal conductivity of a conducting material and hence obtain Wiedemann-Franz law.

(OR)

(b) Explain the band theory of solids in detail and classify solids into conductors, semiconductors and insulators with neat diagram.

12. (a) Write a note on carrier transport in n-type and p-type semiconductors.

(OR)

(b) Explain with necessary theory the Hall Effect and the Agni experimental method to determine the electrical  conductivity of a semiconductor. Explain any four applications.

13. (a) What are ferrites? Describe the different types of ferrites structure with suitable diagrams and mention its applications.

(OR)

(b) Describe the working of magnetic hard disc based on GMR sensor. Mention its advantages and disadvantages.

14. (a) Explain absorption and emission of light in metals, insulators and semiconductors.

(OR)

(b) Describe in detail, the principle construction and the xull bas working of OLED with a neat diagram.

15. (a) Discuss in detail quantum confinement and quantum structures in nano materials.

(OR)

(b) Explain the synthesis mechanism and physical properties of CNTs with a neat sketch and mention its application.

Anna University Model Question Paper - 2

Answer ALL questions

PART A (10 x 2 = 20 marks)

1. What is meant by a free electron?

2. What are forbidden bands?

3. Define the term mobility of a semiconductor.

4. Mention the uses of Ohmic contact.

5. Define magnetic susceptibility and permeability.

6. The dielectric constant of a He gas at NTP is 1.0000684. Calculate the electronic polarizability of He atoms if the gas contains 2.7 x 10²⁵ atoms/m³ and hence evaluate the radius of the He atoms. Given E0 = 8.85 × 10^-12 F/m

7. Define carrier generation and recombination.

8. What are excitons? Give its types.

9. What is meant by tunnelling?

10. Define Coulomb blockade effect.

PART B (5 x 16 = 80 marks)

11. (a) Deduce mathematical expression for electrical conductivity and thermal conductivity of a conducting material and hence obtain Wiedemann. Franz law. (16)

Or

(b) Obtain Eigen values and Eigen functions of an electron enclosed in a 3-D potential box. (16)

12. (a) Derive the intrinsic carrier concentration for intrinsic semiconductor.(16)

Or

(b) Explain the fabrication of the power transistor with applications. (16)

13. (a) (i) Explain the different types of polarization mechanisms involved in a dielectric material (10)

(ii) Explain its frequency and temperature dependence. (6)

Or

(b) What are the different types of dielectric break down in dielectric medium? Discuss in detail the various types of dielectric breakdown. (16)

14. (a) Explain the theory and working of LED. (16)

Or

(b) Explain the construction and working of a semiconductor diode laser (laser diode) with diagram. (16)

15. (a) Discuss density of states in quantum well, quantum wire and quantum dot. (16)

(or)

(b) Describe the carbon nano tubes with their properties and applications. (16)