1. (a) Explain how Newton’s rings are formed in the reflected light.
(b) Derive the expressions for the diameters of dark and bright rings.
(c) Newton’s rings are observed in the reflected light of wavelength 5900 A0. The diameter of tenth dark ring is 0.5 cm. Find the radius of curvature of the lens used.
2. (a) What is meant by diffraction of light? Explain it on the basis of Huygen’s wave theory.
(b) What are the types of diffraction and give the difference between them.
(c) What is the difference between Interference and Diffraction?
3. (a) What is meant by double refraction?
(b) Explain briefly options axis and its characteristics.
(c) Discuss the construction of a nicol prism.
4. (a) Explain the purpose of an active medium in a gas laser.
(b) With the help of suitable diagrams, explain the principle, construction and working of a helium-neon laser.
5. (a) Give an example of engineering application in which you would use a material with a low value of specific heat and a high value of specific heat.
(b) Discuss the variation of thermal conductivity of a solid with temperature.
(c) Explain the terms:
i. drift velocity
ii. relaxation time
iii. collision time and
iv. mean free path.
6. (a) How are the dielectric materials classified?
(b) Write short notes on “Porcelain”.
7. (a) Describe the hysteresis of a ferro-magnetic material.
(b) Explain the properties and applications of ferrites.
(c) Calculate the paramagnetic susceptibility at room temperature for iron oxide, when the material density is 5× 1028 atoms / m3.
8. (a) What is meant by dislocation?
(b) Explain the role of dislocation in the strength of crystals.
(c) Explain the mechanism of creep in materials.