1(a) Why light is
categorized in the category of electromagnetic waves? (4 Marks)

(b) State and explain
Fermat's principle of extremum path and use it to deduce the laws of
reflection and refraction of light. (6 Marks)

(c) What do you
understand by the power of a lens? Calculate the power of two thin
lenses of focal length f1 and f2 separated by a distance d. (6 Marks)

(d) A glass dumbbell of
length one meter and refractive index 1.5 has ends of radius of
curvature 5 cm. Calculate the position of the image due to reflection
at one end only, when the object is at a distance of 40 cm from one
end. (4 Marks)

2(a) Define cardinal
points of a system of co-axial lenses. Describe how you would
determine experimentally the principal planes of a combination of two
thin lenses separated by a distance. (6 Marks)

(b) Describe nodal
assembly methods to locate cardinal points of a lens system
experimentally. Explain its working with particular reference to the
characteristics of nodal points. (6 Marks)

(c) What is the advantage
of using matrix method in paraxial optics? (4 Marks)

(d) The focal length of
each lens of Ramsden's eyepiece is 4 cm by matrix formulation. Find
the focal length and determine the positions of the cardinal points.
(4 Marks)

3(a) Derive the condition
for the combination of two thin prisms to produce mean deviation
without net dispersion. Derive an expression for the net mean
deviation. (6 Marks)

(b) Enumerate the various
defects of image formation by an optical system. Explain the methods
of removing them. (4 Marks)

(c) Explain the terms
entrance pupil and exit pupil. (6 Marks)

(d) Light travels to a
target and back in 0.5 sec in carbon disulphide. Calculate the
distance of the target if the refractive index of the carbon
disulphide is 1.46. (4 Marks)

4(a) What is the
difference between oscilatory motion and wave motion? (4 Marks)

(b) What is normal and
anomalous dispersion? Derive Sellmeier's equation for the refractive
index of a dielectric medium. (6 Marks)

(c) Prove Snell's law of
reflection and refraction taking the oblique incidence of
elctromagnetic wave on an interference between two dielectric media.
(6 Marks)

(d) Find the velocity of
a plane wave in a loss less medium having a relative permittivity of
5 and relative permeability of 1. (4 Marks)

5(a) What are coherent
sources? How are they realized in practice? Describe a method for
determining the refractive index of a gas using the interference
phenomena. (8 Marks)

(b) What are the
conditions for sustained interference pattern? (4 Marks)

(c) What will happen if
wedge shaped film is placed in white light? (4 Marks)

(d) In a Newton's rings
experiment, the diameter of 10th ring changes from 1.4 to 1.27 cm
when a drop of liquid is introduced between the lens and the glass
plate. Calculate the refractive index of the liquid. (4 Marks)

6 (a) Explain the
construction of Fresnel's half period zones. (6 Marks)

(b) Give the theory of
diffraction grating. Describe in detail how you would use a
transmission grating for measuring the wavelength of light. (6 Marks)

(c) Discus Fraunhofer
diffraction pattern of a straight edge. (4 Marks)

(d) An optical filter has
a line width of 1.5 nm and mean wavelength 550 nm. With white light
incident on the filter, calculate (i) coherent length and (ii) the
number of wavelengths in the wave train. (4 Marks)

7 (a) Explain Rayleigh
criterion for resolution and discuss it in relation to the resolving
power of a microscope. (6 Marks)

(b) What is meant by
optical rotation? State any two laws of optical rotation. (6 Marks)

(c) State and explain the
law of Malus. (4 Marks)

(d) Calculate the
thickness of a double refracting plate capable of producing a path
difference of λ/4 between extra
ordinary and ordinary waves. Given μo=
1.53 μe
= 1.54 and λ = 5890Å. (4 Marks)

8(a)
Explain some important properties of hologram. (4 Marks)

(b)
Describe various mechanisms of dispersion in optical fibers. Explain
the effect of dispersion on the bandwidth of optical communication
channel. (6 Marks)

(c)Explain
stimulated Raman scattering. How can it be explained using quantum
concept? (6 Marks)

(d)At
what temperature are the rates of spontaneous and stimulated emission
equal? Assume λ = 5000Å. (4 Marks)

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