VPCOE, Baramati
Engineering Physics
Question Bank (3-4 Marks Ques.)
Interference, Diffraction and Sound Engineering
General Questions:
1. Central spot in Newton’s rings pattern in reflected light is always dark. Explain.
2. ‘Newton’s rings are circular but air-wedge fringes are straight’ Explain the statement.
3. Show that the fringe width of wedge shaped films is inversely proportional to the angle of
wedge.
4. Why an excessively thin film appears black in reflected light?
5. What is the principle behind construction of antireflection films?
6. Will there be any effect on the Newton’s rings pattern if few drops of transparent liquid is
inserted between plano-convex lens and plane glass plate? Why?
7. Explain why fringes get closer as the order of the fringes increases.
8. Draw the ray diagram of light reflecting from a wedge shaped film to produce interference
pattern and hence state the conditions for constructive and destructive interference.
9. Explain any one application of interference.
10. What is Fraunhofer diffraction? How its requirements are achieved in a laboratory?
11. Explain the effect of variation of slit width on the diffraction pattern obtained using a single slit.
12. State any three requirements an auditorium has to fulfill in order to be acoustically good and
explain the measures that can be taken to meet these requirements.
13. Distinguish between intensity of sound and loudness of sound.
14. What is air-borne noise? How it can be avoided?
15. Write any three properties of ultrasonic waves.
16. What is echo-sounding? State any two applications based on echo-sounding technique.
17. Explain the difference between reverberation and echo.
Unit 1 - Interference
Sr. Question
Marks
1 What is thin film? Explain why a thin film when illuminated by white light
3
appears colored when observed in reflected light?
2 A wedge shaped film is illuminated with monochromatic light. Obtain an
4
expression for number of dark bands per unit length (bandwidth).
3 What are Newton’s rings? Explain why density of Newton’s rings increases
3
as we move away from the centre.
4 Explain how Newton's rings setup can be used for the determination of 3 / 4
wavelength of monochromatic source of light. Derive necessary equation.
5 Explain how Newton's rings setup can be used to determine the refractive 3 / 4
index of a transparent liquid. Derive necessary equation.
6 Explain the use of interference as anti-reflective coating.
3/4
7 Explain how interference can be used to test the flatness of a glass plate.
3
8 Explain how interference can be used for measurement of thickness of a
3
thin film.
Diffraction
Sr. Question
Marks
1 What is diffraction of light? Explain types of diffraction with a neat
3/4
diagram.
2 In the case of diffraction due to single slit explain how the width of central
4
maxima depends on width of the slit
3 In the case of diffraction due to single slit explain how the width of central
4
maxima depends on the wavelength of light.
4 What is diffraction grating? Write the equation of maxima and minima for
3
resultant intensity of light with the meaning of each symbol, when
monochromatic light is diffracted from grating.
VPCOE, Baramati
Engineering Physics
5
6
Question Bank (3-4 Marks Ques.)
Obtain an expression for resolving power of grating.
Explain resolving power. Write the expression for resolving power. Explain
the factors on which resolving power depends.
7 Explain diffraction at a circular aperture. What are Airy’s disks? Write the
condition for Fraunhoffer diffraction for circular aperture.
Unit 2 - Sound Engineering
Sr. Question
1 Explain how velocity of sound depends on the properties of the medium
and temperature.
2 Explain the terms intensity and loudness of sound. State how the unit of
decibel is used for comparison of two sound levels.
3 Explain (a) timber of sound (b) reflection of sound
4 What is sound echo? Explain the conditions in which echo is produced?
5 Explain the terms reverberation and reverberation time. What are the
remedies over controlling reverberation time?
6 Explain Sabine’s formula for calculation of reverberation time.
7 Explain the qualities that sound absorbing materials are expected to have.
8 Explain the types of sound absorbing materials.
9 Explain what are different types of noises that can be troublesome in an
auditorium?
Ultrasonic
1 Explain (a) Piezoelectric effect (b) Magnetostriction effect
2 Explain various methods for detection of ultrasonic waves.
3 Explain properties of Ultrasonic waves.
4 What is echo sounding? How this method is useful in finding the distance
of objects using technique SONAR.
5 What is echo sounding? How this method is useful in measuring depth of
sea using technique SONAR.
6 What is echo sounding? How this method is useful in measurement of
thickness using non destructive testing.
7 Explain how flaw detection in metals can be determined using ultrasonic
waves.
8 Explain the process of cavitation in ultrasonic.
9 Explain engineering applications of ultrasonic waves.
10 Explain medical applications of ultrasonic waves.
4
3
4
Marks
3/4
3/4
4
3/4
4
3/4
3
3
3
4
3/4
4
4
4
4
3/4
3/4
3
3
Polarization, Lasers and Solid State Physics
General Questions:
1.
2.
3.
4.
5.
6.
7.
Distinguish between ordinary and extra-ordinary ray.
Explain how light can be polarized by reflection.
Derive an expression for the thickness of a quarter wave plate.
Derive an expression for the thickness of a Half wave plate.
How unpolarized light can be polarized by selective absorption?
State any three differences between Ruby laser and He-Ne laser.
In He-Ne laser, He is filled under the pressure 1 mm of Hg while Ne is filled under the pressure
of 0.1 mm of Hg. Explain the statement.
8. In He-Ne laser, Why the diameter of quartz tube in which the He-Ne mixture is filled is kept
small?
VPCOE, Baramati
Engineering Physics
Question Bank (3-4 Marks Ques.)
9. Explain how and why lasers are used in communication.
10. State any three properties of laser and one application each based on that property.
11. Define the following: 1. Metastable state 2. Active substance 3. Pumping
12. Draw the ray diagram showing recording and reconstruction of hologram.
13. How is holography different from ordinary photography?
14. An analyzer was kept in the path of light to test the state of polarization. When the analyzer was
turned by 360 degrees, no change in intensity was observed. Explain what conclusion you can
draw from this observation. What is the requirement to arrive at discrete conclusion?
15. State the advantages of Hall effect.
16. Draw the energy band diagram of N-type semiconductor at 1. Very low temperature 2.
Moderately low temperature 3. High temperature
17. Draw the energy band diagram of 1. Intrinsic semiconductor 2. Moderately doped P-type
semiconductor 3. Heavily doped P-typed semiconductor
18. Define Fermi energy in conductors and explain Fermi-Dirac probability distribution function.
19. Explain photovoltaic effect and hence define 1. Short circuit current 2. Open circuit voltage
20. Discuss the merits and demerits of solar cells.
Unit 3 – Polarization
Sr. Question
Marks
1 What is polarization of light? Define plane of polarization and plane of
3
vibration.
2 What is polarization of light? Explain what is (a) plane polarized light (b)
4
circularly polarized light (c) elliptically polarized light.
3 State and explain law of Malu’s.
3/4
4 State different methods for production of plane polarized light. Explain how
4
polarization of light is achieved by reflection.
5 State different methods for production of plane polarized light. Explain how
4
polarization of light is achieved by dichroism.
6 State different methods for production of plane polarized light. Explain how
4
polarization of light is achieved by double refraction.
7 What is law of Malu’s? Show that the intensity of the light passing through
3/4
the polarizer is half of the intensity of light incidents on it.
8 What is double refraction? Draw a neat diagram of a crystal showing
4
double refraction. What is (a) ordinary ray (b) extraordinary ray?
9 Differentiate between ordinary ray and extraordinary ray.
3/4
10 Differentiate between positive crystal and negative crystal.
3/4
11 What is double refraction? Draw neat diagrams showing propagation of
4
light through a birefringent crystal when light incidents along (a) parallel to
optic axis (b) perpendicular to optic axis and (b) inclined to optic axis.
12 What are retardation plates? Obtain expression for thickness of Half Wave
4
Plate.
13 What are retardation plates? Obtain expression for thickness of Quarter
4
Wave Plate.
14 What are optically active materials? Explain (a) dextrorotatory and (b)
3
levorotatory materials.
15 What is (a) optical activity (b) specific rotation? Write the expression for
4
specific rotation explaining meaning of all the terms.
16 On the basis of polarization of light explain the mechanism of LCD devices. 3 / 4
Laser
Sr. Question
Marks
1 Any three or four definitions (a) Sponteneous emission, (b) Stimulated
3/4
VPCOE, Baramati
Engineering Physics
Question Bank (3-4 Marks Ques.)
emission, (c) Population inversion (d) Pumping (e) Metastable state (f)
Lasing (g) Resonant cavity
2 What is laser? Explain special properties of laser.
3 With the help of energy band diagram explain construction and working of
semiconductor laser.
4 State and explain the advantages of diode/semiconductor laser.
5 Draw neat and labeled energy diagrams for (a) He-Ne laser and (b) Ruby
laser
6 What are the advantages of fiber optic communication?
7 Describe propagation mechanism of light wave in optical fibers.
8 Draw a neat block diagram of the fiber optics communication system and
explain the role of its components.
9 Explain the process of holography recording and reconstruction.
10 Explain industrial applications of laser.
11 Explain applications of laser in medical field.
Unit 4 – Solid State Physics
Sr. Question
1 Explain in brief how free electron theory explains electrical conductivity
and thermal conductivity of solids, and relation between electrical and
thermal conductivity of solids (Wiedemann–Franz law). What are the
limitations of this theory?
2 Explain the effect of temperature, light and impurity on conductivity of
metals.
3 Explain the effect of temperature, light and impurity on conductivity of
semiconductors.
4 Write the formula for the Fermi Dirac probability distribution function.
Draw in the same figure the Fermi Dirac probability versus electron energy
at T=0K, T1 and T2 (where T2 > T1 > 0k). Explain the significance of the fig.
5 Explain the terms (a) density of states (b) Effective mass of electron
6 Explain how Fermi energy level depends and vary with temperature for Ntype (or P-type semiconductors).
7 Explain how Fermi energy level depends and vary with doping (impurity)
concentration.
8 Explain the terms – (a) Diffusion (b) Drift Current
9 Give the energy band picture of a PN junction when in (a) Forward bias
and (b) Reverse bias
10 Give the energy band picture of a NPN transistor when in (a) Equilibrium
mode (b) Biased mode
11 Write the expression for Hall Coefficient explaining the meaning of each
term involved in it. How Hall Coefficient is used to (a) determine the type of
semiconductor (b) determine the concentration of charge carriers
12 Explain photovoltaic effect. How the fill factor is obtained for a solar cell
from its IV characteristics.
13 On the basis of energy band diagram explain the working of solar cell.
14 State merits and demerits of solar cell. State any two applications of solar
cell.
4
4
4
4
4
4
4
4
3/4
3/4
Marks
4
3
3
4
4
3/4
3/4
4
4
4
3/4
4
4
4
VPCOE, Baramati
Engineering Physics
Question Bank (3-4 Marks Ques.)
Wave Mechanics, Superconductivity and Physics of Nanoparticles
General Questions:
1.
2.
3.
4.
State and explain any three properties of matter waves
State Heisenberg’s Uncertainty principle. How it gets modified for the pair Energy and Time?
Using Uncertainty principle, show that electron cannot exist in the nucleus.
What are the conditions required to be fulfilled by a wavefunction in order to consider it
acceptable?
5. What is the importance of a wavefunction in wave mechanics?
6. Draw the energy band diagram and explain the working of tunnel diode.
7. A particle is trapped in a rigid box in the nth energy state. At how many points it will be found
with highest probability and at how many points there is zero probability of finding it?
8. Define the following: A. Critical temperature B. Critical Magnetic Field C. Critical current.
9. Distinguish between type I and type II superconductors.
10. What is Meissner effect? Explain an application based on this effect.
11. Explain the use of nanoparticles in medicine.
Unit 5 – Wave Particle Duality
Sr. Question
Marks
1 Explain De-Broglie hypothesis of matter waves. Derive the relation for De4
Broglie wavelength.
2 State de-Broglie’s hypothesis and derive the expression for De Broglie
4
wavelength for a particle in terms of kinetic energy.
3 State de-Broglie’s hypothesis and derive the equation for de-Broglie’s
4
wavelength for an electron when it is accelerated through a certain
potential difference.
4 State and explain properties of matter waves.
4
5 Show that Phase Velocity of matter wave is greater than the speed of light.
3/4
6 Show that Group Velocity of a wave packet is equal to particle velocity
3/4
7 Define phase velocity and group velocity. What the contradiction in terms
4
of velocity is observed when we compare the phase velocity with the
particle velocity? How this contradiction is overcome by the concept of
group velocity?
8 State and explain Heisenberg’s principle.
3/4
9 With the help of Heisenberg’s uncertainty principle, show that an electron 3 / 4
cannot sustain inside the nucleus.
Wave Equations
Sr. Question
Marks
1 Explain physical significance of  and | 2|.
4
2 What do you understand by wave function of a moving particle? What does
4
the square of the wave function signify?
3 What is Schrödinger’s equation? Explain the significance of Schrödinger’s
3
equation at atomic level.
4 Explain tunneling effect in quantum mechanics. Explain it by giving any 3 / 4
real life example.
5 What is tunnel diode? What are the advantages of tunnel diode over a
3
conventional diode?
6 What is scanning tunneling microscope (STM)? Explain the principal over
4
which an STM works. What are the advantages and applications of STM?
VPCOE, Baramati
Engineering Physics
Main Ques. Bank
Vidya Pratishthan's College of Engineering, Baramati
First Year
Question Bank [Subject: Physics]
Unit –I Interference & Diffraction
Interference
Q1) In case of thin film of uniform thickness derive expression for path
difference in reflected light and state conditions for constructive and
destructive interference.
[06]
Q2) Obtain an expression for the optical path difference in the reflected
system in case of wedge shaped film & hence derive the conditions for
constructive & destructive interference.
[06]
Q3) Explain the use of thin films as anti reflecting coatings.
[04]
Q4) Explain how phenomenon of interference is utilized in testing the
plainness of a surface.
[04]
Q5) What are Newton’s rings? Prove that in Newton’s rings by reflected light
the diameter of dark rings are proportional to the square root of the
natural numbers.
[06]
Q6) What are Newton’s rings? Prove that in Newton’s rings by reflected light
the diameter of bright rings are proportional to the square root of the odd
natural numbers.
[06]
Q7) Explain the formation of Newton’s rings. How can these be used to
determine the refractive index of the liquid ?
[06]
Q8) A soap film of refractive index 4/3 & of thickness 1.5 X 10-4 cm is
illuminated by white light incident at an angle of 600. In reflected
light there is a dark band corresponding to a wavelength of 5 X 10-5 cm.
Calculate the order of interference (n) of the dark band.
[04]
-7
Q9) A beam of monochromatic light of wavelength 5.82 X 10 m falls normally
on a glass wedge with the wedge angle of 20 seconds of an arc. If the
refractive index of the glass is 1.5, find the number of interference fringes
per cm of the wedge length.
[04]
1
VPCOE, Baramati
Engineering Physics
Main Ques. Bank
Q10) In a Newton’s rings experiment the diameter of the 15th dark ring was
found to be 0.590cm and that of 5th dark was 0.336cm. If the radius of
the plano-convex lens is 100cm, calculate the wavelength of light used.
[04]
Diffraction
Q1) Discuss the theory of Fraunhofer’s diffraction at a single slit & derive the
Condition for maxima.
[07]
Q2) Explain the theory of diffraction grating. Obtain the condition for formation
of principle maxima.
[06]
Q3) What is diffraction of light? What are the types of diffraction? Distinguish
between them.
Q4) What is diffraction grating ? How it is obtained?
[02]
Q5) A beam of monochromatic light of wavelength  passes through a slit of
width ‘a’ the rays after undergoing the Fraunhofer diffraction through an
angle  produced a resultant disturbance at some point P given
by E = Em ( sin/).
Obtain the condition for principal maxima, minima & secondary maxima.
Draw the Intensity distribution curve.
[04]
Q6) What is meant by resolving power of an optical instrument? Obtain an
expression for the resolving power of grating.
[06]
Q7) Explain:
a) Diffraction of light
b) Fresnel and Fraunhofer’s diffraction
[06]
Q8) What is the highest order spectrum, which may be seen with monochromatic
light of wavelength 6000A0 by means of diffraction grating with 5000
lines / cm.
[04]
Q9) Calculate the minimum number of lines in a grating which will just
resolve the sodium lines in the first order spectrum. The wavelengths
are 5890A0 and 5896 A0.
[04]
2
VPCOE, Baramati
Engineering Physics
Main Ques. Bank
Q10) What is the longest wavelength that can be observed in the third order for a
transmission grating having 7000 lines per cm? Assume normal incident.
[04]
Unit –III Polarisation & Laser
Polarisation
Q1) Write a short note o polarization by reflection.
[04]
Q2) Write a note on polarization by refraction. (Pile of plates)
Q3) State and explain Brewster’s law.
[04]
Q4) Write a short note on double refraction.
[04]
Q5) State and explain Law of Malus.
[04]
Q6) Explain double refraction on the basis of Huygen’s wave theory.
[06]
Q7) What are the retardation plates? Explain half wave & quarter wave plate
[05]
Q8) What do you understand by a quarter and half wave plate? Deduce their
thickness for a given wavelength in terms of their refractive index.
Q9) Write a note on Optical activity.
[06]
[04]
Q10) A glass plate of refractive index 1.5 is to be used as a polarizer.
What is the angle of polarization and angle of refraction?
[04]
Q11) Polariser and analyzer are set with their polarizing directions parallel
so that the intensity of transmitted light is maximum, through what
angle either be turned so that the intensity be reduced to
a) 50 % b) 25 % of the maximum intensity
[04]
Q12) Calculate the thickness of half wave plate of quartz for given light of
wavelength 5000A0. Given that
e = 1.5553 and o = 1.544
3
[04]
VPCOE, Baramati
Engineering Physics
Main Ques. Bank
Laser
2
Define the terms:
i) Stimulated absorption
ii) Spontaneous emission
iii) Stimulated emission
iv) Pumping
v) Meta-stable state
vi) Population inversion
vii) Active medium.
Explain the terms:
3
i) Stimulated absorption
ii) Population inversion
iii) Pumping
Distinguish between Spontaneous emission & Stimulated emission.
4
What are lasers? State the properties of lasers.
[4]
5
What are properties of lasers? Explain any one.
[4]
6
What is population inversion? How it is achieved by optical pumping?
[4]
7
What is population inversion? Why it is necessary for lasing?
[4]
8
What is Meta-stable state? What role do such states play in the
1
[1]
each
[2]
each
[4]
operation of lasers?
9
[4]
What do you understand by a negative temperature state? How can
it be achieved?
[4]
10 Explain the operation of Ruby laser with neat labeled diagram.
[6]
11 Explain how lasing action is achieved in a semiconductor laser?
[6]
12 With
the
help
of
energy
band
diagram
explain
working
of
semiconductor laser.
[6]
13 Explain construction & working of He-Ne laser.
[6]
14 Explain any one application of laser.
[4]
15 Explain in brief – i) Spatial coherence
ii) Temporal coherence
[4]
16 What is holography? Explain Recording & Reconstruction of a
[6]
Hologram.
***************************************************
4
VPCOE, Baramati
Engineering Physics
Main Ques. Bank
Unit IV: Semiconductor Physics:
1
2
Describe in brief the formation of energy bands in solids.
What is Fermi energy? Show the location of Fermi energy levels in intrinsic and
extrinsic semiconductors.
3 Classify the elements in to conductors, insulators and semiconductors on the basis of
band theory of solids.
4 What is Fermi function? Show that the Fermi level lies at the centre of the energy gap
in an intrinsic semiconductor.
5 Explain why a potential difference develops across an open circuited P -N Junction.
6 Explain the terms valance band, conduction band and forbidden energy gap.
7 What are transistors? Explain the working of PNP / NPN transistor.
8 Give the energy band picture of P-N junction diodes and explain the effect of biasing
on the band picture.
9 Discuss the working of NPN transistors. Explain with respect to the energy band
diagram.
10 “P-N junction is a unidirectional device”. Explain.
11 Write a note on solar cell.
12 Derive the expression for conductivity in an intrinsic and extrinsic semiconductor.
13 Explain the working of a P-N junction diode under forward and reverse bias on the
basis of energy level diagram.
14 Discuss application of a solar cell.
15 Write a note on the construction and characteristics of a solar cell.
16 Explain Hall Effect and Hall coefficient.
17 Explain the process that takes place in and around the depletion layer.
18 Explain the working of a solar cell. Give the significance of the cell parameters Isc , Voc
and fill factor .
19 Derive an expression for conductivity in a metal.
Problems:
1 The mobilities of carriers in intrinsic germanium sample at room temperature are μn =
3600cm2 /volt –sec and μp = 1700cm2 /volt-sec. If the density of electrons is same as
holes and is equal to 2.5x 1013 per cm3, calculate the conductivity. (Ans. 2.12 mho/m)
2 Calculate the number of acceptors to be added to a germanium sample to obtain the
resistivity p= 10 ohm.cm. Given, μ = 1700cm2 /volt-sec. (Ans. 3.676x1014 per cm3)
3 At room temperature the conductivity of a silicon crystal is 5x 10 -4 mho/cm. If the
electron and hole mobilities are 0.14 m2/ volt-sec and 0.05 m2/ volt-sec, determine the
density of carriers. (Ans. 1.64 x 1016 /m3)
4 The specific density of tungsten is 18.8 g/cm3 and its atomic wt. is 184.0. Assume that
there are teo free electrons per atom. Calculate the concentration of free electrons. Av.
No. = 6.025 x 1023 /g mole. (Ans. 2.5 x1023 / cm3 )
5 Compute the conductivity of copper for which μe = 34.8 cm2 volt-sec and d=
8.9gm/cm3. Assume that there is one free electron per atom. Av. No. = 6.025 x 1023 /g
mole. At wt. of Cu = 63.5. If an electric field is applied across such a copper bar with
an intensity of 10 V/cm, find the average velocity of free electrons. (Ans. 47.02 x 10 -4
mho/cm, 348 cm/sec.)
6 The resistivity of copper wire of diameter 1.03 mm is 6.51 ohm per 300 m. The
concentration of free electrons in copper is 8.4 x1028 /m3. if the current is 2A, find the
(a) mobility, (b) drift velocity, (c) conductivity.
(Ans. 0.413 m2 /volt-sec, 0.286 x 10-20 m/sec, 55.5 x 108 mho/m)
7 Calculate the energy gap in silicon if it is given that it is transparent to radiation of
wavelength greater than 11000 A0 (Ans. 1013 eV)
[4]
[6]
[6]
[6]
[2]
[3]
[6]
[6]
[6]
[2]
[6]
[6]
[6]
[4]
[6]
[6]
[2]
[6]
[6]
[4]
[4]
[4]
[4]
[4]
[4]
[4]
VPCOE, Baramati
8
Engineering Physics
Main Ques. Bank
An N- type semiconductor is ti has a resistivity of 10 ohm – cm. Calculate the number
of donor atoms which must be added to achieve this.
Given: μe = 500 cm2 / volt-sec. (Ans 12.5x 1023)
Unit V
1. Wave Particle Duality
1
2
3
4
5
6
7
8
9
State and explain Heisenberg’s uncertainty principle? Illustrate it by an experiment on
diffraction at a single slit.
Starting from the uncertainty principle for the position-momentum pair, derive the
uncertainty principle for the Energy-time pair.
Show that the phase velocity of a matter wave is c2/v, where c is the speed of light and
v is the velocity of the particle.
Show that the group velocity of a matter wave is equal to the particle velocity.
Explain how the concept of a de Broglie group wave is associated with the
Heisenberg’s uncertainty principle.
With the help of a neat diagram, explain the phenomenon of diffraction of an electron
from a single slit on the basis of Heisenberg’s uncertainty principle.
State the de Broglie hypothesis and derive the equation of de Broglie wavelength in
terms of energy.
Show that the wavelength associated with an electron, accelerated by a potential
difference of V volts, is given by h
.
2meV
What is the de Broglie wavelength of an electron at rest? Give reasons.
[4]
Marks
[6]
[4]
[4]
[6]
[4]
[6]
[4]
[4]
[3]
Problems:
1
Calculate the de Broglie wavelength of (a)1 keV electron (b)1 keV proton and (c)
[4]
1KeV neutron.
2 The wavelength of yellow spectral emission line of sodium is 5893A. At what kinetic
[4]
energy would an electron have that wavelength as its de Broglie wavelength?
3 An electron and a photon each have a wavelength of 2A. Calculate their (a) momenta
[4]
and (b) their energies.
4 What accelerating voltage would be required for the electrons of an electron
microscope if the microscope is to have the same resolving power as could be obtained
using 100 keV gamma rays?
[4]
5 Imagine playing baseball in a universe (not ours) where the Planck constant is 0.60 Js.
What would be the uncertainty in the position of a 0.50kg baseball that is moving at 20
m/s along an axis if the uncertainty in the speed is 1.0 m/s?
[4]
6 Compare the uncertainties in the velocities of an electron and a proton confined in a
[4]
10A box.
7 The position and momentum of a 1 keV electron are simultaneously determined. If its
position is located to within 1A, what is the percentage of uncertainty in its
momentum?
[4]
8 Show that the uncertainty in the velocity of a particle is of the order of the particle
velocity itself.
[4]
9 An electron and a proton have the same kinetic energy. Which of them has the greater
de Broglie wavelength? Why?
[4]
10 If you double the kinetic energy of a particle, how does its de Broglie wavelength
change? (b) What if you double the speed of the particle?
[4]
11 The mass of an electron is 9.1 x 10 -31 kg and that of a bullet is 10g. If both of them
travel with a velocity of 10 m/s, calculate their de Broglie wavelengths. Why do we
observe wave behavior for an electron but not for a bullet?
[4]
VPCOE, Baramati
Engineering Physics
Main Ques. Bank
2. Wave Equations
1
2
3
4
5
6
7
8
Derive the Schrodinger’s time independent equation by setting up a wave equation and
using the de Broglie wavelength.
2
What is the physical significance of and  
Derive an expression for the energy levels and the wave functions of a particle
enclosed in an infinite potential well.
What is normalization of a wave function?
2
Draw and  for a particle in (a) a rigid box and (b) a non-rigid box. Explain the
differences between the two.
Write down the Schrodinger’s equation in the different regions of a finite potential
well. State the boundary conditions that the wave function must satisfy.
Derive the Schrodinger’s time dependent equation starting from the Schrodinger’s time
independent equation.
What is tunneling effect? Describe the I-V characteristics of a tunnel diode on the basis
of tunneling phenomenon in its energy bands.
[6]
[4]
[7]
[4]
[4]
[6]
[6]
[6]
Problems:
1
An electron is trapped in a one-dimensional, infinitely deep potential energy well of
width 1A.
(a) What is the ground state energy?
(b) How much energy is required to transfer the electron from the ground state
to the second excited state? If this energy is provided by a photon, what is
its wavelength?
(c) Once the electron has been excited to the second excited state, what
wavelengths of light can it emit by de-excitation?
2
1) A ground state electron is trapped in the one-dimensional infinite potential well
with width 1A.
(a) What is the probability that the electron can be detected in the left one-third
of the well (0 < x <L/3)?
(b) What is the probability that the electron can be detected in the middle onethird of the well (L/3 < x < 2L/3)?
3 What must be the width of an infinite potential well if an electron trapped in the state
for n=3 to have energy of 4.7eV?
4 An electron is trapped in a rigid box in the n=17state. How many points of (a) zero
probability and (b) maximum probability does its matter wave have?
5 A proton and an electron are trapped in the ground state of identical rigid boxes. At the
centre of the well, is the probability density for the proton greater than, less than or
equal to that of the electron? Give reason.
6 If a nucleus is approximated by a one-dimensional infinite potential well with width L
= 1.4 x 10-14 m then what is the ground state energy of (a) an electron and (b) a proton
confined to the nucleus?
7 An electron in a rigid box 2.5 A wide is in the ground state. How much energy must it
absorb if it is to jump to the state with n = 4?
8 The lowest possible energy for a certain particle trapped in a rigid box is 1 eV. (a)
What are the next two higher energies the particle can have? (b) If the particle is an
electron, how wide is the box?
9 Consider a potential energy barrier whose height is 6 eV and whose thickness is 7 A.
What is the energy of an incident electron whose transmission coefficient is 0.001?
10 Rank the following pairs of quantum states for an electron states for a particle confined
to an infinite well according to the energy difference between the states, greatest first:
[3]
[4]
[4]
[4]
[4]
[4]
[3]
[3]
[4]
[4]
[3]
each
[4]
[4]
VPCOE, Baramati
Engineering Physics
Main Ques. Bank
(a) n=3 to n=1, (b) n=5 to n=4 and (c) n=4 to n=3. Give reasons.
11 Three infinite wells with width L, 2L and 3L have an electron each in their n=10 state.
Rank the wells, with reasons, according to (a) number of maxima for the probability
density of the electron and (b) the energy of the electron, greatest first.
12 By what factor should the width of an infinite potential well be reduced to decrease the
ground state energy of the trapped particle to half?
13 An electron, trapped in a finite potential well, is in its ground state. Are (a) its de
Broglie wavelength, (b) the magnitude of its momentum and (c) its energy greater than,
the same as, or less than they would be if the potential well were infinite? Give reasons
for each briefly.
[4]
[3]
[6]
Unit VI:
1. Superconductivity:
1
2
What are superconductors? Define critical temperature.
What is the significance of critical temperature, critical magnetic field for
superconductors?
3 Explain the following terms : i) Zero Electrical resistance
ii) Persistent current.
4 Explain the isotope effect & its significance
5 Explain the Meissner effect.
6 Explain the Meissner effect. What important property of superconductors it explain?
7 Explain the perfect diamagnetism in superconductors.
8 Distinguish between Type I & Type II superconductors.
9 Explain Type I & Type II superconductors with examples.
10 What is superconductivity? Explain the BCS theory of Superconductors.
11 Explain DC * AC Josephson effect.
12 Explain the use of superconductors in electromagnets & transmission lines.
[2]
[4]
[6]
[6]
[6]
[6]
[6]
[6]
[6]
[6]
[6]
[4]
2. Physics of Nano-particles:
1
2
3
4
5
6
7
8
9
10
11
12
13
14
Define Nanotechnology.
What is the significance of particles in the nano-domain?
Discuss the mechanical & electrical properties of nano-materials.
Discuss the optical & magnetic properties of nano-materials.
Give a brief account of the properties of nano-materials.
Give a brief description of different methods of synthesis of nano-materials.
What are the advantages of synthesizing nano-materials by chemical methods?
Define colloids and nano-materials with reference to colloids. Give examples of
colloids.
Explain briefly the theory of colloids.
Explain briefly how colloids are synthesized by the chemical route.
Explain with the help of Lamer diagram the nucleation and growth of nano-particles.
What is “Ostwald ripening” of nano-particles?
How are metal nano-particles synthesized by the colloidal route?
Discuss the following applications of nanotechnology.
[1]
[2]
[6]
[6]
[7]
[3]
[3]
[3]
[3]
[3]
[3]
[1]
[2]
(i) Electronics (ii) Energy (iii) Space & defense
15 Discuss the following applications of nanotechnology.
[6]
(i) Automobiles (ii) Medical (iii) Nanotechnology & Environment
16 Give a brief account of the applications of Nanotechnology.
[7]
[7]
VPCOE, Baramati
Engineering Physics
Questions asked in Unipune Exam
Unit 1: Interference
1
2
3
4
5
6
7
8
9
10
11
12
Basics of Interference
What is thin film? How interference is produced in thin films when light incidents on it?
Interference in thin film of uniform thickness
A thin film of uniform thickness is illuminated by monochromatic light. Obtain the
conditions of darkness and brightness of the film as observed in reflected light.
Derive an expression for path difference in reflected light for thin parallel film and show
that the interference pattern in the reflected and transmitted system is complementary.
When seen by reflected light, why does an excessively thin film appear to be perfectly
black when illuminated by white light?
A thin film is illuminated by white light appears colored when observed in reflected light.
Explain why?
Interference in thin film of non-uniform thickness
Draw diagram showing interference in reflected light in a thin wedge shaped film. Write
down only the mathematical conditions for maximum and minimum intensity of light in
reflected system.
A wedge shaped film is illuminated with monochromatic light. Obtain an expression for
number of dark bands per unit length (bandwidth).
Newton’s rings
Explain the formation of Newton’s rings. Obtain an expression for the diameter of dark
th
rings in reflected system. What will happen to the diameter of n ring if air film is
replaced by water film? Explain.
Explain with diagram and necessary theory how Newton’s rings can be obtained in
laboratory? Why in Newton’s rings centre is always dark for reflected system.
Prove that for the Newton's rings in reflected light, the diameters of dark rings are
proportional to the square root of natural numbers.
14
Explain why Newton’s rings come closer with increase in their diameter orders.
Explain how Newton's rings setup can be used for the determination of wavelength of
monochromatic source of light. Derive necessary equation.
Explain how Newton's rings setup can be used to determine the refractive index of a
transparent liquid? Derive necessary equation.
Applications of Interference
Explain the use of thin film as anti-reflective coating.
15
16
Explain how interference can be used to test the flatness of a glass plate.
Explain how interference can be used for measurement of thickness of a thin film.
13
Dec 09 – 7m
May 10 – 7m
May 11 – 7m
Dec 11 – 7m
Dec 08 – 3m
May 12 – 4m
Dec 08 – 7m
Dec 11 – 7m
Dec 09 – 7m
Dec 10 – 7m
May 11 – 6m
May 12 – 3m
Dec 08 – 4m
May 09 – 4m
May 09 – 3m
Diffraction
1
2
3
3
4
5
6
Basics of diffraction
Explain diffraction of light.
What is diffraction of light? What are the types of diffraction? Distinguish between
them.
Explain (a) diffraction (b) resolving power
Fraunhoffer diffraction at single slit
Obtain the conditions for principal maximum and minimum in Fraunhofer diffraction
due to a single slit.
Derive equation for resultant intensity of light waves in Franhoffer’s diffraction at a
single slit.
Explain Fraunhoffer diffraction at a single slit and obtain the condition for principal
maxima and minima. Draw the intensity distribution curve.
With necessary theory show that the central maxima lies at =0 in Fraunhoffer
Dec 09 – 3m
May 11 – 6m
Dec 11 – 4m
Dec 09 – 6m
Dec 10 – 6m
May 10 – 7m
Dec 11 – 6m
VPCOE, Baramati
7
8
9
10
11
12
13
14
15
16
17
Engineering Physics
Questions asked in Unipune Exam
diffraction at single slit.
In the case of diffraction due to single slit explain how the width of central maxima
depends on width of the slit and the wavelength of light.
Fraunhoffer diffraction due to grating
Give the theory of plane diffraction grating. Obtain the condition for the formation of
th
n order maximum.
What is diffraction grating? Obtain the condition for formation of principal maxima and
minima in grating.
Give the theory of plane diffraction grating. Obtain the condition for maxima and
minima.
Write a short note on diffraction at circular aperture? What is Airy disk?
What is diffraction grating? Give the equation of resultant intensity of light with the
meaning of each symbol, when monochromatic light is diffracted from grating. Obtain
the equation of maxima and minima.
Resolving power of grating
Obtain an expression for resolving power of grating.
State the factors on which the resolving power of grating depends.
What is resolving power of grating? Obtain an expression for resolving power of grating.
Obtain an expression for the resolving power of grating. On what factors does it
depend?
Scattering
What is scattering of light? Why it takes place in atmosphere? On its basis explain why
sky appears blue. Why the sun appears red & orange at the time of sunrise and sunset.
Dec 08 – 6m
Dec 11 – 6m
May 12 – 7m
May 11 – 6m
Dec 08 – 3m
Dec 08 – 2m
May 12 – 7m
Dec 10 – 6m
May 09 – 6m
May 10 – 6m
Unit 2: Sound Engineering & Ultrasonic
1
2
3
4
5
6
7
8
9
10
11
12
13
Sound Engineering
Explain how velocity of sound depends on temperature
Explain the terms intensity and loudness of sound. State how the unit of decibel is
used for comparison of two sound levels.
Explain the term timber of sound.
Explain how reflection of sound takes place.
What is sound echo? Why and how it is produced?
Explain the terms reverberation and reverberation time. What are the remedies
over controlling reverberation time?
Explain Sabine’s formula for calculation of reverberation time.
What are the qualities that sound absorbing materials are expected to have. Explain
different types of sound absorbing materials.
What are different types of noises that can be troublesome in an auditorium? How
these types of noises can be controlled?
Explain what are the requirements for good acoustics of a hall
Methods of Production of Ultrasonic
Piezoelectric Effect and Oscillator
What are ultrasonics? What are different methods of their production? explain any
one method with suitable diagram.
Explain piezoelectric effect
14
What is piezoelectric effect? Explain how piezoelectric effect can be used for
generating ultrasonic waves.
Explain how piezoelectric effect can be used for generating ultrasonic waves.
15
Magnetostriction effect and oscillator
Explain magnetostriction effect.
Dec 11 – 6m
May 09 – 3m
May 10 – 1m
May 12 – 6m
Dec 09 – 6m
May 10 – 6m
May 09 – 3m
VPCOE, Baramati
16
17
18
19
20
21
22
23
24
25
26
27
28
Engineering Physics
Questions asked in Unipune Exam
Explain what magnetostriction effect is. Draw a neat labeled diagram for the
production of ultrasonic by magnetostriction oscillator.
Detection and Applications of Ultrasonic
Explain various methods for detection of ultrasonic waves.
Explain any one application of ultrasonic.
Explain echo sounding technique and cavitation with one example of each.
Discuss the use of ultrasonic for flaw detection.
Explain the principle of echo sounding describing any two applications of ultrasonic
waves where this principle is used.
Explain how the velocity of ultrasonic waves is determined by ultrasonic
interferometer.
Explain echo sounding technique. Discuss any two applications of ultrasonic based
on this technique.
What are ultrasonic waves? Describe any two engineering applications of ultrasonic
waves.
Explain echo sounding and cavitation techniques as an application of ultrasonic
waves.
Explain industrial/engineering applications of ultrasonic waves (soldering, cutting,
welding).
Explain medical applications of ultrasonic.
What is cavitation? How this principle is used for ultrasonic cleaning?
Dec 08 – 6m
Dec 10 – 6m
May 11 – 6m
Dec 11 – 3m
Dec 08 – 4m
Dec 08 – 3m
May 09 – 7m
May 10 – 6m
May 09 – 6m
May 12 – 6m
Dec 09 – 6m
Dec 10 – 6m
May 11 – 6m
Unit 3: Polarization
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
Basics of Polarization
Explain the terms: (a) electromagnetic wave (b) unpolarized light (c) polarization (d)
polarized light (e) partially polarized light (f) plane of vibration (g) plane of
polarization
Explain the terms (i) optical activity, (ii) pile of plates.
Which are different methods of production of plane polarized light?
How plane polarized light can be obtained using arrangement of pile of plates?
What is dichroism? How polarization of light can be achieved using dichroism?
State and explain Malu’s law. What is the intensity of the light transmitted through
polarizer.
Double refraction, Huygen’s theory
Define plane of polarization and plane of vibration. Explain the phenomenon of
double refraction in calcite.
What is double refraction? Explain it on the basis of Huygen’s wave theory.
Explain the term double refraction and hence explain in the phenomenon of it on
the basis of Huygen’s theory.
Explain Huygen’s theory of double refraction.
What is polarization by double refraction? Explain it on the basis of Huygen’s
theory. What are positive and negative crystals?
State points of differences between: positive and negative crystals with examples.
State points of differences between: ordinary and extraordinary rays
Propagation of light within birefringent crystal
Explain giving diagram, the nature of refraction observed in case of a calcite crystal
when (a) optic axis parallel to the refracting surface and lying in the plane of
incidence (normal incidence) (b) optic axis perpendicular to the refracing surface
and lying in the plane of incidence (normal incidence)
Using Huygen’s principle, construct refracted beams in calcite crystal when
(a) optic axis in plane of incidence and parallel to the crystal surface
(b) optic axis in plane of incidence and perpendicular to the crystal surface
(c) optic axis in plane of incidence and inclined to the crystal surface
Retardation plates: QWP and HWP
May 09 – 6m
Dec 10
Dec 09 – 6m
May 12 – 6m
May 10 – 6m
Dec 10 – 6m
May 11 – 6m
Dec 08 – 6m
Dec 11 – 6m
VPCOE, Baramati
16
17
18
19
20
21
22
23
Engineering Physics
Questions asked in Unipune Exam
What are the retardation plates? What are their types? Obtain expression for their
thickness.
What are the retardation plates? Deduce the thickness of a QWP for a given
wavelength in terms of its refractive indices.
What are the retardation plates? Deduce the thickness of a HWP for a given
wavelength in terms of its refractive indices.
Polaroid and Specific rotation
Explain the term dichroism. What are polaroids and how are they produced?
Describe the construction and working of Laurent’s half shade polarimeter and
explain how it can be used for the determination of specific rotation of an optically
active substance.
What is optical activity and specific rotation?
What are Polaroid?
Explain how the phenomenon of polarization of light is used in LCD displays.
May 12 – 6m
Dec 09 – 6m
Dec 11 – 6m
Dec 08 – 6m
Unit 3: Laser
1
2
3
4
5
6
7
8
9
10
11
Basics of laser
Explain: Spontaneous emission
May-09 (2m), Dec-11 (2m)
Explain: Stimulated emission
Dec-08 (2m), May-09 (2m), Dec-09 (2m), Dec-11 (2m)
Explain: Population inversion
Dec-08 (2m), May-09 (2m), Dec-09 (2m), Dec-10 (2m), May-11 (2m), Dec-11 (2m),
May-12 (2m)
Explain: Pumping / optical pumping
Dec-08 (2m), May-09 (2m), May-10 (2m), Dec-10 (2m), May-11 (2m)
Explain: Metastable State
Dec-08 (2m), Dec-11 (2m)
Explain: Lasing
Explain: Resonant cavity
What are the special properties of laser?
Semiconductor Laser
With the help of energy band diagram explain construction and working of
semiconductor laser.
State and explain the advantages of diode/semiconductor laser over He-Ne laser.
He-Ne Laser
Explain construction and working of He-Ne laser.
Dec-11 (2m)
May-10 (2m)
Dec-08 (2m)
May-09 (4m)
May 12 (6m)
Dec-09 (4m)
May-10 (4m)
Dec-11 (4m)
May-09 (6m), May-10 (6m), May-11 (7m), Dec-12 (6m)
12
Ruby Laser
Explain construction and working of Ruby laser with the help of energy level diagram.
Also comment on Ruby laser is a pulsed laser.
Dec-08 (7m), May-09 (6m), Dec-09 (6m), May-10 (7m), Dec-10 (7m), Dec-11 (7m)
13
14
15
16
17
18
Applications of laser
State any six applications of laser.
Explain any one application of laser in brief.
Optic Fiber
What are the advantages of fiber optic communication?
Describe propagation mechanism of light wave in optical fibres.
Draw a neat block diagram of the fibre optics communication system and explain the
role of any four components in the system.
Holography
What is holography? Explain the process of holography recording and reconstruction.
Dec-08 (3m)
May-09 (4m)
Dec-09 (4m)
May 12 (4m)
Dec-10 (6m)
Dec-11 (6m)
VPCOE, Baramati
Engineering Physics
Questions asked in Unipune Exam
Unit 4: Solid State Physics
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
Band Theory solids
Explain terms (a) valence band (b) conduction band (c) band gap energy
Explain classification of solids into conductors, semiconductors and insulators on the
basis of energy band theory.
Free electron theory
Explain in brief how free electron theory explains electrical conductivity and thermal
conductivity of solids, and relation between electrical and thermal conductivity of solids
(Wiedemann–Franz law). What are the limitations of this theory?
Conductivity of metals and semiconductor
Derive an expression for conductivity of intrinsic and extrinsic semiconductors.
Explain the effect of temperature, light and impurity on conductivity of metals and
semiconductors.
Fermi level and Fermi function
Write down an expression for the probability of occupancy of a particular state of an
electron in an intrinsic semiconductor.
Write the formula for the Fermi Dirac probability distribution function. Draw in the same
figure the Fermi Dirac probability versus electron energy at T=0K, T1 and T2 (where T2 > T1
> 0k). Explain the significance of the figure.
Using Fermi-Dirac probability distribution function, derive an expression for the position
of Fermi energy level in the intrinsic semiconductor.
Define Fermi level in conductors and semiconductors. Show that Fermi level lies at the
centre of energy gap in an intrinsic semiconductor.
Density of states
Explain the term density of states
Effective mass of electron
Why the mass of electron is variable inside the solid when it moves under the influence
of external field. Explain the concept of effective mass of electron. Hence explain the
concept of hole.
Dependence of Fermi energy level on temperature and doping cocentration
Explain how Fermi energy level depends and vary with temperature for N-type (or P-type
semiconductors).
Explain how Fermi energy level depends and vary with doping (impurity) concentration.
Explain the terms – (a) Diffusion (b) Drift Current
PN Junction diode
Give the energy band picture of a PN junction diode and explain the effect of biasing on
the band picture. Dec-08 (7m), May-09 (7m), Dec-09 (7m), May-10 (7m)
Draw energy band diagrams for PN junction diode in forward bias and reverse bias
condition.
Energy band picture of transistor
Give the energy band picture of an NPN/PNP transistor and explain the effect of biasing
on the band picture.
Hall effect and Hall coefficient
Explain Hall effect in semiconductors. Derive the equation of Hall voltage and Hall
coefficient.
May 12 (7m), Dec-09 (6m), May10 (6m), Dec-10 (6m)
Photovoltaic effect
Explain photovoltaic effect. How the fill factor is obtained for a solar cell from its IV
characteristics.
Solar Cell
Explain the construction and working of solar cell. Explain its IV characteristics.
State merits and demerits of solar cell. State any two applications of solar cell.
Dec-08 (6m)
May-10 (6m)
May-11 (6m)
Dec-10 (6m)
May-11 (6m)
Dec-10 (4m)
Dec-11 (6m)
May-09 (6m)
May 12 (6m)
May-11 (7m)
May-09 (6m)
Dec-08 (4m)
VPCOE, Baramati
Engineering Physics
Questions asked in Unipune Exam
Unit 5: Wave Mechanics - Wave Particle Duality
1
2
3
4
5
6
7
8
9
10
11
12
13
De-Broglie hypothesis, matter waves and energy of electron
Explain in short De-Broglie hypothesis of matter waves.
Derive the expression for De Broglie wavelength for a particle in terms of kinetic
energy.
State de-Broglie’s hypothesis and derive the equation for de-Broglie’s wavelength in
terms of (a) energy (b) for an electron
Explain De-Broglie hypothesis of matter waves and obtain the equation of De-Broglie
wavelength of matter waves in terms of energy by analogy of radiation. Also obtain
equation of De-Broglie wavelength of an electron.
Derive the expression for De Broglie wavelength for an electron when it is accelerated
through a certain potential difference.
Properties of matter waves
State and explain properties of matter waves.
Classify following properties of De-Broglie waves into true or false
a. De-Broglie waves are probability waves.
b. The wavelength of De-Broglie waves is inversely proportional to the
momentum of the particle.
c. The group velocity of the De-Broglie waves is given by vg=vparticle.
d. De-Broglie waves are significant for subatomic particles.
e. De-Broglie waves associated with bounded particles are quantized.
f. De-Broglie waves are associated only with moving material particles.
Phase velocity and group velocity
Show that
(a) Phase velocity of matter wave is c2/v, where c is the speed of light and v is
velocity of particle
(b) Group velocity of a wave packet is equal to particle velocity
Explain the concept of group velocity and phase velocity. Show that group velocity is
equal to the velocity of the particle.
Explain the concept of group velocity and phase velocity. Derive expression for group
velocity with which a wave group travels.
Explain the concept of phase velocity and group velocity. Show that for a particle the
phase velocity comes out to be greater than the velocity of light.
Heisenberg’s uncertainty principle
State and explain Heisenberg’s uncertainty principle.
State Heisenberg’s uncertainty principle. Illustrate it by the experiment of electron
diffraction at a single slit.
Dec-08 (2m)
May-09 (4m)
May 12 (6m)
Dec-09 (6m)
May-11 (6m)
Dec-11 (6m)
May 12 – 7m
May-10 (6m)
Dec-10 (7m)
Dec-08 (6m), May-09 (6m), Dec-09 (6m), May-10 (6m), Dec-10 (6m), May-11 (6m)
14
15
16
17
Identify and mark which of the following statements of Heisenberg’s uncertainty
principle are incorrect. In-front of the incorrect statement, write the correct
statement.
x  p y  h
  p y  h
x  p z  h
 x  t  h
Dec-11 (5m)
x  E  h
Show that Heisenberg’s uncertainty principle is applicable to the energy and time.
If uncertainty in the position of a particle is equal to de-Broglie wavelength, they
show that uncertainty in velocity is equal to the velocity of the particle.
With the help of Heisenberg’s uncertainty principle, show that an electron cannot
sustain inside the nucleus.
May-12 (4m)
Unit 5: Wave Mechanics - Wave Equations
1
Wave Function
2
Explain physical significance of  and | |.
May-09 (6m)
Dec-09 (4m)
VPCOE, Baramati
2
3
4
5
6
7
8
9
10
11
12
13
Engineering Physics
Questions asked in Unipune Exam
What do you understand by wave function of a moving particle? What does the square
of the wave function signify?
Schrödinger’s Equations
What is Schrödinger’s equation? Derive Schrödinger’s time dependent equation.
Obtain three dimensional time independent Schrödinger’s wave equation.
Derive time dependent Schrödinger’s wave equation.
State Schrödinger’s time independent and time dependent equations and state any one
difference between them. What are the basic requirements for solution of the
Schrödinger’s equation to be acceptable?
Particle enclosed in rigid box of infinite potential well
Derive expression for the energy levels and wave function of a particle enclosed in an
infinite potential well. Give the graphical representation of both the terms.
Derive equation of energy and wave function when a free particle is trapped in an
infinite potential well.
Obtain the wave function for a particle moving in a rigid box. Also obtain the expression
for its quantized energy. Highlight the step at which quantization begins.
Discuss the behavior of a particle when it is enclosed in a non-rigid box of finite energy.
Discuss the nature of the wavefunction in the box and outside the box. What are the
conclusions that can be drawn?
Explain tunneling effect in quantum mechanics. Explain it by giving any real life example.
What is tunnel diode? Explain its working on the basis of tunnel diode under forward
and reverse bias on the basis of tunneling effect. What are the advantages of tunnel
diode?
What is scanning tunneling microscope (STM)? Explain construction and working of STM.
What are the advantages and applications of STM?
Dec-10 (4m)
May 12 (6m)
Dec-08 (6m)
May-09 (6m)
Dec-09 (7m)
May-11 (6m)
Dec-10 (7m)
May-11 (6m)
Dec-11 (7m)
May-09 (7m)
May 12 (7m)
Dec-09 (7m)
May-10 (7m)
Dec-11 (7m)
Unit 6: Superconductivity
1
2
3
Basics of Superconductivity
Explain the phenomenon of superconductivity.
Explain what the significance of critical temperature is for superconductors.
Explain: Meissner Effect
Dec-08 (4m)
Dec-10 (2m)
May-12 (2m), Dec-08 (3m), May-09 (3m), Dec-09 (3m), May-10 (3m)
4
Explain: Isotope Effect
5
Explain: Critical magnetic field
6
7
8
Explain: Persistent current
Explain: Critical current density
State and explain Meissner effect. Hence show that susceptibility is negative in
superconducting state.
Type I and Type II Superconductors
Explain Type I and Type II superconductors.
Differentiate between Type I and Type II superconductors on the basis of their response
to the magnetic field and exhibition of the Meissner effect. Support your explanation
with the figures.
BCS Theory
Distinguish between Type I and Type II superconductors.
What is superconductivity? Explain BCS theory for superconductors.
Explain BCS theory of superconductivity.
9
10
11
12
13
Dec-09 (4m), May-10 (4m), Dec-10 (7m), May-11 (6m)
Dec-08 (3m)
May-10 (3m)
May-09 (3m)
Dec-09 (3m)
Dec-09 (3m)
Dec-10 (3m)
May-11 (6m)
May-10 (6m)
Dec-11 (4m)
May 12 (6m)
May 12 (6m)
VPCOE, Baramati
14
15
16
17
18
Engineering Physics
Questions asked in Unipune Exam
Following paragraphs gives 6 statements regarding BCS theory. Rewrite the statements
and underline if they are incorrect.
a. BCS theory indicates electron-lattice-electron interaction through a quantum
of lattice vibration called phonon
b. An electron, while passing through lattice distorts it, and another electron
while passing across the distorted lattice gets attracted due to accumulated
positive charge in the distorted lattice
c. Two electrons cannot exist together despite the presence of phonons.
d. Cooper pairs are Bosons and thus any number of Cooper pairs can be
accommodated in a single low energy state.
e. This leads to coherent propagation of Cooper pairs with lowest possible speeds
and thus hindrances are minimized. This leads to the superconducting state.
f. BCS theory explains why superconductivity is a high temperature, high
magnetic field phenomenon.
Applications of Superconductivity
State any two applications of superconductivity.
Elaborate on any two applications of superconductors.
Josephson Effect
Write a note on Josephson effect.
Explain Josephson effect. What is Josephson junction? Draw its neat labelled diagram.
State any one application of Josephson effect.
Dec-11 (6m)
Dec-08 (2m)
Dec-10 (4m)
May-11 (4m)
Dec-11 (6m)
Unit 6: Physics of Nanoparticles
1
Properties of Nanoparticles
Explain any two properties of nano-materials.
2
Explain optical and electrical properties of nanoparticles.
3
Classify following properties of nanoparticles into optical, electrical and mechanical:
a. Nano particles exhibit change in color, which changes with the change in
their size
b. When nano particles are embedded in plastics, the strength is increased
c. Gold, when synthesized in nanoprticle form, appears red.
d. The IV characteristics of nanoparticles is not linear but is like a staircase.
e. Nanoparticles may acquire superconducting state under some conditions
f. When polycrystalline magnesium is converted into nanocrystalline
2
2
magnesium, the Young’s modulus decreases from 4100 N/m to 3900 N/m .
Synthesis of nanoparticles
Explain the synthesis of metal nanoparticles by colloidal route.
1
2
3
1
2
3
Explain chemical vapour deposition method for manufacturing nano particles.
State any four methods used for synthesis of nano particles and describe any one
method in details.
Applications of nanoparticles
Discuss any one application of nanotechnology.
Explain applications of nano particles in the field of medicine and electronics.
State any seven distinct applications of nanotechnology.
May 12 (6m)
Dec-09 (6m)
Dec-10 (6m)
May-10 (6m)
May-11 (6m)
Dec-11 (6m)
May 12 (6m)
May-09 (6m)
Dec-09 (6m)
May-10 (6m)
May-11 (6m)
Dec-10 (6m)
Dec-11 (6m)
Dec-09 (4m)
Dec-10 (4m)
Dec-11 (7m)