GTU BE 1st and 2nd Semester BSP001 Engineering Physics Summer 2018 Question Paper

Seat No.: _____________________ Enrolment No.:_________________
GUJARAT TECHNOLOGICAL UNIVERSITY
SPFU-SEMESTER-1
st
/ 2
nd
EXAMINATION-Summer 2018
Subject Code: BSP001 Date: 18-05-2018
Subject Name: Engineering Physics
Time: 02:30 to 05:30 Total Marks: 70
Instructions:
1. Attempt any five questions
2. Make suitable assumptions whenever necessary
3. Figures to the right indicate full marks.
Q.1 (a) With neat diagram describe the construction working and applications of
Nd:YAG laser.
07 (b) Write any four points of difference between step index and graded index fibre. 04 (c) An optical fibre core and its cladding have refractive indices of 1.55 and 1.46
respectively. Calculate the critical angle F
C
, acceptance angle F
in(max)
and
numerical aperture.
03

Q.2 (a) With neat diagram describe the construction and working of Piezo-electric
Generator.
07 (b) Write and discuss characteristics of musical sound. 04 (c) An ultrasonic wave of 0.07 MHz sends down a pulse towards the seabed, which
returns after 0.65 s. The velocity of sound in seawater is 1700 m/s. Calculate the
depth of sea and wavelength of pulse.
03

Q.3 (a) Give brief explanation about different types of magnetic materials. 07 (b) Write note on angular momentum of a rigid body. 04 (c) Give brief explanation about damped oscillations and resonance. 03

Q.4 (a) Write points of comparison between type-I and type-II superconductors. 07 (b) List the important properties and applications of CNTs. 07

Q.5 (a) What is Meissner effect? Show that superconductor exhibits perfect
diamagnetism.
07 (b) The critical magnetic field at 5 10
3
A/m in a superconductor ring of radius
0.02 m. Find the value of critical current.
03 (c) Define (i) Nano-science and (ii) Nanotechnology. 04

Q.6 (a) What are called reverberation and reverberation time? Write Sabine?s formula of
reverberation time and explain each term.
05 (b) Write the full form of LASER. 02 (c) What are carbon nanotubes (CNTs)? Explain briefly the carbon nanotubes and
their different structures.
07

Q.7 (a) Write and discuss the factors affecting acoustics of buildings and their remedies. 07 (b) Calculate the atomic polarizability of neon. At NTP, the dielectric constant of
neon is 1.0025 and its atomic density is 3.54 10
25
atoms/m
3
.
Take e
0
= 8.85 10
?12
C
2
/ (N m
2
).

04 (c) Initial angular speed of a wheel is 10 rad / s. Its angular displacement in 5 s is 80
rad. Find total angular displacement of the wheel from the beginning to the time
till it stops?
03