JNTU QUESTION PAPER
1. (a) Explain the various types of bonding in solids with suitable examples.
(b) The Madelung constant of KCl is 1.75. Its neighbour separation is 0.314 nm.Find the cohesive energy per atom. [Given that the Repulsive exponent value= 5.77; Ionization energy of potassium = 4.1 eV; Electron affinity of chlorine = 3.6 eV]
2. (a) Distinguish between a matter wave and an electromagnetic wave.
(b) Describe GP Thomson’s experiment to study electron diffraction.
(c) Find the wavelength associated with an electron rose to a potential 1600 V.
3. (a) Explain the following:
i. Electrical resistivity and
ii. Fermi energy.
(b) Explain briefly the quantum free electron theory of metals.
(c) On the basis of band theory how the crystalline solids are classified into metals, semiconductors and insulators?
4. (a) Explain the hysteresis loop observed in Ferro-magnetic materials.
(b) Explain clearly difference between hard and soft magnetic materials.
5. (a) How are ‘superconductors’ classified? Explain their properties.
(b) What is Meissner effect? Explain.
(c) Write notes on the applications of superconducting materials.
6. (a) Describe the various methods to achieve population inversion relating to lasers.
(b) With the help of a suitable diagram, explain the principle, construction and working of a semiconductor laser.
7. (a) Distinguish between light propagation in
i. step index optical fiber and
ii. graded index optical fiber.
(b) Write a note on fiber optic medical endoscopy.
8. (a) Write a detailed note on nanoscience.
(b) Why nanomaterials exhibit different properties? Explain.