GTU BE 1st and 2nd Semester 110011 Engineering Physics Summer 2018 Question Paper

1
Seat No.: ________ Enrolment No.___________
GUJARAT TECHNOLOGICAL UNIVERSITY
BE- SEMESTER? 1
st
/ 2
nd
? EXAMINATION ? SUMMER 2018
Subject Code: 110011 Date: 18-05-2018
Subject Name: Engineering Physics
Time: 02:30 pm to 05:00 pm Total Marks: 70
Instructions:
1. Attempt any five questions.
2. Make suitable assumptions wherever necessary.
3. Figures to the right indicate full marks.
Q.1 (a) Write and explain the factors affecting Acoustic of a building and their
remedies.
07
(b) Describe the principle and the method of producing of ultrasonic waves by
magnetostriction method.
07

Q.2 (a) Discuss the steps to find Miller indices of a given plane with the help of
example.
07
(b) Explain the term Hall-effect, Derive relation between Hall voltage and Hall-
coefficient, State application of it.
07

Q.3 (a) Write note on: Nd:YAG laser 07
(b) What is holography? Discuss the method of construction of hologram. 07

Q.4 (a) Describe the construction of fiber optic cable and compare the advantage of
fiber optic cable over metallic cable.
07
(b) Deduce expression for electrical conductivity of conducting material and hence
obtain Wiedemann Franz law.
07

Q.5 (a) What is superconducting material? List the properties of superconducting
materials and explain in detail.
07
(b) Write note on: CO2 laser. 07

Q.6 (a) What are Nanomaterials? What are the four applications of Nanomaterials? 07
(b) Explain the method of x-ray radiography to detect the exact location of the
flaws.
07

Q.7 (a) A silica optical fiber has a core of refractive index 1.58 and a cladding of
refractive index 1.46. Determine (i) the critical angle at the core-cladding
Interface (ii) the numerical aperture for the fiber and (iii) the acceptance angle
in the air for the fiber.
03
(b) The intensity levels of two sound waves of the same frequency in a medium are
20 dB and 60 dB. What is the ratio of their amplitude?
03
(c) The volume of a room is 2500 m
3
. The wall area of the room is 330 m
2
, the
floor area is 165 m
2
, and the ceiling area is 165 m
2
. The average sound
absorption coefficient (i) for wall is 0.025; (ii) for the ceiling is 0.75; and (iii)the floor is 0.05. Calculate the average sound absorption coefficient and
reverberation time.
04
(d) An ultrasonic source of 0.05 MHz sends down a pulse towards the seabed
which returns after 0.55 s. The velocity of sound in water is 1500 m/s. Calculate
depth of the sea and wavelength of the pulse.
04
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