and 1.553, then find the least thickness for which the ordinary and extraordinary rays
combines and emerge as plane polarized light.

What is Meissner effect? Show that a super conductor is a perfect diamagnet.

The time gap between the excitation of an atom and emission of radiation is 05107
second. Find the uncertainty in the frequency of radiation.

Write three important postulates of Fermi-Dirac Statistics. Also write its distribution
equation

A cinema hall has a volume of 10000 ന്‌. It is required to have a reverberation time 012
seconds. What should be the total absorption of the hall?

Calculate the frequency of ultrasoaic waves that can be generated by a nickel rod of
length 4cm. (Young's modulus of nickel = 207 GPa and density of nickel 8900 kg/m? 0
Calculate the ratio of spontaneous to stimulated emission by an incandescent bulb at
2000 K. Take frequency= 6 x 10'* Hz, Boltzmann Constant k = 1.38x1 021.

What are Fibre optic sensors? Name two different types.

Part-C

Answer any 3 questions. Each question carries 6 marks.

Frame and solve the differential equation of a forced harmonic oscillator

With necessary theory write the formation of interference pattern in an air wedge and
derive an expression for the bandwidth.

You are provided with two nicols and a quarter wave plate. How will you produce
plane polarized, circularly polarized and elliptically polarized light.

State Uncertainty principle. With the help of it, explain the absence of electrons inside
the nucleus,

Answer any 3 questions, Each question carries 6 marks.

Name and explain two methods for the detection of ultrasonic waves. Name any four
medical applications of ultrasonic waves.

What is reverberation and reverberation time? What is its significance? Write the
factors on which the reverberation time depends. Write Sabine's formula.

Outline the principle and working of He-Ne laser.

What is the principle of holography? How is a hologram recorded? Write any two
applications of holography.