Download GTU BE/B.Tech 2019 Winter 1st And 2nd Sem New And Spfu 3110011 Physics Question Paper

Download GTU (Gujarat Technological University) BE/BTech (Bachelor of Engineering / Bachelor of Technology) 2019 Winter 1st And 2nd Sem New And Spfu 3110011 Physics Previous Question Paper

1
Seat No.: ________ Enrolment No.___________

GUJARAT TECHNOLOGICAL UNIVERSITY

BE - SEMESTER ? I & II (NEW) EXAMINATION ? WINTER 2019
Subject Code: 3110011 Date: 02/01/2020

Subject Name: Physics
Time: 10:30 AM TO 01:00 PM Total Marks: 70

Instructions:
1. Attempt all questions.
2. Make suitable assumptions wherever necessary.
3. Figures to the right indicate full marks.

Marks

Q.1 (a)
Define: coefficient of viscosity.
03
(b)
Define Reverberation time and write down the Sabine?s formula of it by
explaining the parameters in it.
04
(c)
What is damping motion? Derive the differential equation and general
solution of damped harmonic motion.
07

Q.2 (a)
Define resonance in an oscillating system.
03
(b)
Draw stress- strain diagram. Explain the main points of it.
04
(c)
Write down the factors affecting the acoustics of an auditorium. Give
remedies.
07
OR
(c) Explain Young?s Modulus, shear modulus, bulk modulus and
Poisson?s ratio.
07
Q.3 (a)
Write down various applications of ultrasonic waves.
03
(b)
Calculate the natural frequency of 50 mm length of a pure iron rod. Given
that Young?s modulus of iron = 11.5?10
10
N/m
2
and density of pure iron =
7.25?10
3
kg/m
3
. Can you use it in a magentostriction oscillator to produce
ultrasonic waves?
04
(c)
Describe production of ultrasonic waves by magnetostriction method. Give
its advantages and limitations.
07
OR
Q.3 (a)
What do you understand by NDT. Give names of few NDT methods.
03
(b)
A Nikel rod having 5 cm length is vibrating at resonance. Calculate the
fundamental frequency of vibration for which ultrasonic waves are
generated. Given that Young?s modulus of Nikel = 2.14?10
11
N/m
2
, density
of Nikel = 8.908 ?10
3
kg/m
3
.
04
(c)
Describe acoustic diffraction method to determine the speed of sound in
liquid with suitable diagram.
07
Q.4 (a)
Explain the phenomenon of superconductivity.
03
(b)
The critical magnetic field of Niobium is 1?10
5
Tesla at 8 K and 2?10
5
Tesla
at 0 K. Calculate the transition temperature of the element.
04
(c)
Write down the applications of superconductors.
07
OR
Q.4 (a)
Describe BCS theory of superconductivity.
03
(b) Derive the formula for time period of a torsional pendulum. 04
(c)
(i) Josephson Junction and its applications 04
(ii) What force is required to stretch a steel wire to double the length when
its area of cross section is 1 cm
2
. Given that Young?s modulus of wire is
7?10
10
N/m
2
. 03

07
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1
Seat No.: ________ Enrolment No.___________

GUJARAT TECHNOLOGICAL UNIVERSITY

BE - SEMESTER ? I & II (NEW) EXAMINATION ? WINTER 2019
Subject Code: 3110011 Date: 02/01/2020

Subject Name: Physics
Time: 10:30 AM TO 01:00 PM Total Marks: 70

Instructions:
1. Attempt all questions.
2. Make suitable assumptions wherever necessary.
3. Figures to the right indicate full marks.

Marks

Q.1 (a)
Define: coefficient of viscosity.
03
(b)
Define Reverberation time and write down the Sabine?s formula of it by
explaining the parameters in it.
04
(c)
What is damping motion? Derive the differential equation and general
solution of damped harmonic motion.
07

Q.2 (a)
Define resonance in an oscillating system.
03
(b)
Draw stress- strain diagram. Explain the main points of it.
04
(c)
Write down the factors affecting the acoustics of an auditorium. Give
remedies.
07
OR
(c) Explain Young?s Modulus, shear modulus, bulk modulus and
Poisson?s ratio.
07
Q.3 (a)
Write down various applications of ultrasonic waves.
03
(b)
Calculate the natural frequency of 50 mm length of a pure iron rod. Given
that Young?s modulus of iron = 11.5?10
10
N/m
2
and density of pure iron =
7.25?10
3
kg/m
3
. Can you use it in a magentostriction oscillator to produce
ultrasonic waves?
04
(c)
Describe production of ultrasonic waves by magnetostriction method. Give
its advantages and limitations.
07
OR
Q.3 (a)
What do you understand by NDT. Give names of few NDT methods.
03
(b)
A Nikel rod having 5 cm length is vibrating at resonance. Calculate the
fundamental frequency of vibration for which ultrasonic waves are
generated. Given that Young?s modulus of Nikel = 2.14?10
11
N/m
2
, density
of Nikel = 8.908 ?10
3
kg/m
3
.
04
(c)
Describe acoustic diffraction method to determine the speed of sound in
liquid with suitable diagram.
07
Q.4 (a)
Explain the phenomenon of superconductivity.
03
(b)
The critical magnetic field of Niobium is 1?10
5
Tesla at 8 K and 2?10
5
Tesla
at 0 K. Calculate the transition temperature of the element.
04
(c)
Write down the applications of superconductors.
07
OR
Q.4 (a)
Describe BCS theory of superconductivity.
03
(b) Derive the formula for time period of a torsional pendulum. 04
(c)
(i) Josephson Junction and its applications 04
(ii) What force is required to stretch a steel wire to double the length when
its area of cross section is 1 cm
2
. Given that Young?s modulus of wire is
7?10
10
N/m
2
. 03

07
2
Q.5 (a)
Write down the properties of LASER light.
03
(b)
What is the wavelength of light of Ruby Laser if the separation between
metastable state and lower energy state is 1.79 eV. Given that Planck?s
constant = 6.64?10
-34
Js.
04
(c)
Describe the construction and working principle of He-Ne LASER with
suitable diagrams.
07
OR

Q.5 (a)
Classify sound on the basis of frequency with suitable examples.
03
(b)
Derive the relationship between Einstein Coefficients.
04
(c)
Write down the various applications of LASER.
07

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