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B2B013 Pages: 2

. The volume of a room is 500 ஈட. The wall area of the room is 250 ന and the floor
area is 150 ന്‌. The average sound absorption coefficient of the wall is 0.03, the floor
is 0.05 and the ceiling is 0.8. Calculate the reverberation time.

A nickel rod of length 10 cm is used in a magnetostriction oscillator. Calculate the
frequency of ultrasonic waves generated. Young’s modulus of nickel is 210 x 10°
N/m? and density of nickel is 8900 kg/m’.

Explain the process of recording and reading a hologram.

With a block diagram, explain the working of an optical communication system.

PART C
Answer any three questions. Each question carries 6 marks.

Frame the differential equation of a forced harmonic oscillator and obtain its solution.
With the help of a neat diagram, explain the formation of diffraction pattern with a
single slit. Deduce the equations for the bright and dark fringes and the width of the
central maxima.

With a neat diagram explain how a nicol prism is constructed. Describe how it
produces plane polarized light.

Write down the Schrodinger equation for a particle in a one dimensional infinite
square well potential and obtain the equation for wave function of the particle.

PART D
Answer any three questions. Each question carries 6 marks.

Explain the thermal method of detection of ultrasonic waves. Describe one method of
non destructive testing using ultrasonic waves. Mention four medical applications of
ultrasonic waves.

What are the characteristics of musical sound? What are the factors affecting
acoustics of a building?

What are the basic components of a laser system? How are these requirements
satisfied in the case of a Ruby laser?

Define numerical aperture of an optic fibre. Obtain an expression for the numerical
aperture of a step index fibre.

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