1.a. How interferene in wedge shaped film is used to test optical flatness of given glass plate.

1.b. What is diffraction grating?What is the advantage of increasing the number of lines in the grating.

1.c. With neat ray diagram explain the concept of total internal reflection (TIR).

1.d. Differentiate between spontaneous and stimulated emission.

1.e. Find cylindrical coordinates of $(3i+4j+k)$.

1.f. In newtons Ring pattern what is will be the order of the dark ring which will have double the diameter of $40^{th}$ dark ring.

1.g. Draw the block diagram of CRT(cathode ray tube) and explain the parts of it.

2.a. Derive the Condition of maxima and minima due to interference of light from thin film of uniform thickness.

2.b. Derive the formula for numerical aperture of step index fibre and give its physical significance.The N.A. of an optical fibre is 0.5 and core refractive index is 1.54. Find the refractive index of cladding.

3.a. Discuss the fraunhofer diffraction at single slit and obtain Condition for minima. In plane transmission grating the angle of diffraction for second order principal maxima for wavelength $5 × 10^{-5}$ is $35^0$. Calculate number of lines / cm. On diffraction grating.

3.b. What is the difference between photography and holography? Explain Holography technique to obtain 3D image of an object.

4.a. what is the divergence of vector field $F = x^2 yz\bar{i} +xz \bar{j}$

4.b. Explain how A.C. voltage and its frequency is measured using CRO.

4.c. A wedge shaped air films having an angle of 40 seconds is illuminated by monochromatic light and fringes are observed vertically through a microscope. The distance Measured between consecutive bright fringes is 0.12 cm. Calculate the wavelength of light used.

5.a. Explain Newton's rings experiment and show the diameters of $n^{th}$ dark rings are proportional to square root of natural numbers.$

5.b. Write Maxwell's equations and give its physical significance.

5.c. Explain construction and working of atomic force microscope.

6.a. Explain different types of carbon nanotubes and give its applications.

6.b. Explain construction and working of Nd:YAG laser.

6.c. Write a note on electrostatic focussing.