Download PART-B

MODEL QUESTION PAPER (Anna University, Tirunelveli)
PART A (10 X 2 =20)
1. How is acoustic grating formed?
2. What is the principle of SONAR in ultrasonics?
3. Distinguish between spontaneous and stimulated emission.
4. What is meant by holography?
5. Distinguish between step-index and graded index fibre.
6. Calculate the numerical aperture and acceptance angle of a fibre with the core
index of 1.54 and cladding 1.50.
7. What is the principle of electron microscope?
8. Calculate the de-broglie wavelength of an electron, which has been accelerated
from rest on application of potential of 400V.
9. Define polymorphism and allotropy.
10. What are Frenkel and Schottky imperfections?
PART-B
11. (a) (i) Explain how ultrasonic waves can be produced by using piezoelectric
crystal.
(ii) Write any 4 applications of ultrasonics. (12+4)
OR
(b) In ultrasonic NDT what are three different scan displays in common use? (16)
12. (a) For atomic transitions, derive Einstein relation and hence deduce the
expressions for the ratio of spontaneous emission rate to the stimulated emission
rate. (16)
OR
(b) Describe with theory the construction and working of CO2 laser. (16)
13. (a) Define numerical aperture and derive expression for the numerical aperture
and acceptance angle of fibre in terms of refractive index of the core and cladding
of the fibre. (16)
OR
(b) What are the different types of fibre optic sensors? Explain the working of any
two sensors.
14. (a) (i) What are the basic postulates of quantum theory of light?
(ii) Derive Planck’s law of radiation. (4+12)
OR
(b) Derive time dependent Schrodinger wave equation and hence derive time
independent Schrodinger wave equation. (16)
15. (a) What is packing factor? Obtain packing factors for SC, BCC and FCC
structures. (16)
OR
(b) (i) What are miller indices?
(ii) Derive an expression for interplanar spacing for (hkl) planes of a cubic
structure. (4+12)
MODEL QUESTION PAPER (Anna University, Trichy)
PART A (10 X 2 =20)
1. How are ultrasonic waves used to measure depth of sea?
2. A quartz crystal of thickness 0.001m is vibrating at resonance. Calculate the
fundamental frequency. Density of quartz crystal 2.650x108 Kg/m3 and Young’s
modulus for quartz 7.9x1010N/m2.
3. Give the important characteristics of laser.
4. List our any 4 applications of laser in engineering.
5. What are active and passive sensors?
6. Calculate the numerical aperture and acceptance angle and the critical angle of a
fibre having core index 1.5 and cladding index 1.45.
7. What is the physical significance of wave function?
8. Give the special features of Quantum theory of radiation.
9. What are Bravais lattice?
10. Define Miller indices and draw the crystal planes for (110) and (001).
PART-B
11. (a) (i)Explain how inverse piezoelectric effect can be applied for the production of
ultrasonic waves using piezoelectric oscillator. (8)
(ii) Describe a method of determining the wavelength of ultrasonic waves in
liquid using the principles of diffraction. (8)
OR
(b) (i) Explain in detail various scanning mode using ultrasonic waves. (8)
(ii) Write a note on sonogram with neat sketch. (8)
12. (a) (i) Explain the modes of vibration of CO2 molecule. (6)
(ii) Describe the construction and working of CO2 laser with neat diagram.
(10)
OR
(b) (i) With suitable diagram explain how laser action is achieved in
homojunction and heterojunction in Ga-As laser. (8)
(ii) Explain how a hologram is recorded and reconstructed using coherent
beam? (8)
13. (a) (i) Derive an expressions for acceptance angle and numerical aperture of an
optical fibre. Bring out the differences between step index and graded index fibre.
(12)
(ii) Write a note on fibre optic pressure sensor. (4)
OR
(b) Explain in detail about sources and detectors involved in optical fibre
communication with necessary diagram. (16)
14. (a) Give the theory of Compton effect and briefly explain its experimental
verification. (16)
OR
(b) (i) Derive time-independent Schrodinger wave equation. (6)
(ii)Using time-independent Schrodinger wave equation normalize the wave
function of electron trapped in a one-dimensional potential well. (10)
15. (a) (i) Define the term coordination number and atomic radius. Calculate the
coordination number and atomic radius for BCC and FCC structure. (10)
(ii) Calculate the lattice constant and distance between two adjacent atoms for
potassium bromide crystal (FCC lattice) having the density and molecular weight of
2700 Kg/m3 and 119 resp.
OR
(b) (i) Show that the face centered cubic and hexagonal close packed structure
have the atomic packing factor. (10)
(ii) Show that for the cubic structure the interplanar distance d in terms of
miller indices and cell edge a is given by
a
d=
h2 + k2 + l2
MODEL QUESTION PAPER (Anna University, Coimbatore)
PART A (20 X 2 =40)
1. Mention any 4 properties of ultrasonic waves.
2. What is cavitation? Mention its use.
3. What is piezo-electric effect?
4. What is sonogram? Mention its application.
5. Calculate the number of photons emitted per second at a wavelength 632.8nm by
He-Ne laser of 3mW power.
6. What is the role of helium and nitrogen in CO2 laser?
7. What is the principle of semiconductor laser?
8. Define the terms ‘stimulated emission and population inversion’.
9. What is the role of cladding in an optical fibre?
10. What is splicing? Mention the two types of splicing.
11. List four factors that cause loss in optical fibre.
12. What is an Endoscopes? Mention its use.
13. Deduce Rayleigh-Jeans law from Planck’s law for radiation.
14. The wavelength of X-ray photon is doubled when it is scattered through an angle
of 900 by a target material. Find the incident wavelength.
15. What is the physical significance of the wave function?
16. The de-broglie wavelength of an electron is 1.226A0. What is the accelerating
potential?
17. Determine the lattice constant for FCC crystal having atomic radius 1.476A0.
18. Draw the planes having miller indices (110) and (111) in cubic system.
19. Which crystal structure is having least coordination number? Give example.
20. Define the terms polymorphism and allotropy.
PART-B
21. (a) Explain the principle, construction and working of magnetostriction oscillator
for the production of ultrasonics.
(b) With the neat diagram, discuss the pulse echo system.
22. Writes notes on:
(a) Detection of ultrasonics.
(b) Laser in welding and cutting
23. (a) Describe the construction and working of Nd-YAG laser.
(b) Explain recording and reconstruction of a hologram.
24. (a) Discuss the light propagation in an optical fibre and obtain the expression for
numerical aperture.
(b) Explain fibre optical communication system with neat block diagram.
25. (a) Discuss in detail the classification of optical fibres based on mode and
refractive index.
(b) Explain the fibre optic temperature sensor with neat diagram.
26. (a) Based on quantum concepts derive planck’s radiation formula.
(b) Describe an experiment to verify Compton effect.
27.(a) Solve schrodinger’s wave equation for the particle in a one dimensional box.
(b) Compare SEM and TEM.
28. (a) Obtain expressions for packing factor for FCC and HCP structures.
(b)Give an account of point defect in crystals.
C 3908
B.E./B.Tech. DEGREE EXAMINATION, JANUARY 2009
Second Semester
Civil Engineering
PH 2111 – ENGINEERING PHYSICS – I
(Common to all branches B.E./B.Tech.)
(Regulation 2008)
Time: Three hours
Maximum : 100 marks
Answer ALL questions
PART A – (10 X 2 = 20 marks)
1. What is sonar? Mention two applications of it.
2. A ultrasonic generator consists of a quartz plate of thickness 0.7 mm and density 2800
kg/m3. Find the fundamental frequency of ultrasonic waves if the Young’s modulus of
quartz is 8.8 x 10 10 N/m2.
3. Define population inversion and metastable state.
4. What are the advantages of heterojunction semiconductor laser over homojunction?
semiconductor laser?
5. Distinguish between step index and graded index fiber.
6. A silica optical fiber has a core refractive index of 1.5 and cladding refractive index of
1.47. calculate the critical angle at he core-cladding interface.
7. What is Compton wavelength and calculate its value.
8. What is the physical significance of wave function .
9. State the values of coordination number of HCP structure and diamond structure.
10. The lattice constant for a FCC structure is 4.938A0. Calculate the interplanar
spacing of (220) planes.
PART –B (5X16=80marks)
11. (a) (i) What is inverse Piezo electric effect?
(ii) Describe the construction and working of a piezo electric generator to
produce ultrasonic waves.
(iii) State the merits and demerits of magnetostriction oscillator. (2+10+4)
OR
(b) (i) What is acoustic grating?
(ii) Describe the method of determining the velocity of ultrasonic waves using
acoustic grating.
(iii) Mention any four applications of ultrasonic waves.
(2+10+4)
12. (a) (i) Distinguish between spontaneous and stimulated emission of radiation.
(ii) Describe the construction and working of He-Ne laser with energy level
diagram.
(iii) What are Einstein’s A and B coefficients? (4+10+2)
OR
(b) (i)Describe the Vibrational modes of CO2 molecule.
(ii) Describe the construction and working of CO2 laser with energy level
diagram.
(iii) For a semiconductor laser, the band gap is 0.8eV. what is the wavelength
of light emitted from it. (3+10+3)
13. (a) (i) Define acceptance angle and numerical aperture.
(ii) Derive the expression Sin n12 – n22.
(iii) Describe a method of measuring the temperature of a source using fiber
optic sensor. (2+8+6)
OR
(b) (i) Describe a fiber optic communication system.
(ii) Describe the principle, construction and working of light emitting diode.
(iii) State the advantages of light emitting diodes in electronic display. (6+8+2)
14. (a) (i) What is Compton effect?
(ii) Derive an expression for the wavelength of scattered X ray photon from a
material.
(iii) A X ray photon of wavelength 1.24 x 10-3A0 is scattered by a free electron
through an angle 900. Calculate the energy of the scattered photon. (2+10+4)
OR
(b) (i) Derive the Schrodinger’s time independent wave equation.
(ii) Apply Schrodinger’s wave equation to a particle in one-dimensional box
and calculate the Eigen value and Eigen function. (8+8)
15. (a) (i) What are Bravais lattice?
(ii) Derive an expression for the interplanar spacing in a cubic structure.
(iii) With a neat diagram describe the edge dislocation. (2+8+6)
OR
(b) (i) Define Atomic radius and packing fraction.
(ii) Describe a HCP structure. Show that for an HCP structure c/a =  8/3 and
hence calculate the packing fraction for the HCP structure.
(iii) The lattice constant of a metal with cubic lattice is 2.88 A0. The density of
metal is 7200 Kg/m3. calculate the number of unit cell present in 1Kg of the metal.
ENGINEERING PHYSICS I (PH2111) (MAY/JUNE 2009)
PART –A
1. Calculate the frequency of ultrasonic waves that can be generated by a nickel rod
of length 4 cm. (Young’s modulus of nickel = 207 Gpa and density of nickel=
8900 Kg/m3)
2. Write a note on cavitations.
3. Give the principle of semiconductor diode laser.
4. Mention any four applications of laser in medicine.
5. Define acceptance angle in optical fiber communications.
6. What are the types of sensors used in fiber optic communication?
7. In Compton scattering, the incident photon have a wavelength 0.5nm. Calculate
the wavelength of scattered radiation if they are viewed at an angle 450.
8. Explain the principle of transmission electron microscope.
9. Differentiate polymorphism and allotropy.
10. Write a short note on burger vector.
PART-B
11. (a) (i) Write down the properties of ultrasonic waves.
(ii) Describe the principle, construction and working of piezo-electric
oscillator.
OR
(b) (i) Describe the various non-destructive testing methods.
(ii) Explain the types of ultrasonic imaging systems.
12. (a) (i) What is spontaneous and stimulated emission?
(ii) Write down the conditions for population inversion.
(iii) What is pumping action? Explain the methods commonly used for
pumping action.
OR
(b) (i) Explain the construction and reconstruction of a hologram.
(ii) In detain explain the principle, construction and working of four level solidstate laser.
13. (a) (i) Explain in detail the losses in optical fiber with basic attenuation
mechanisms.
(ii) Give the advantages of fiber-optic communication
OR
(b) (i) Find the numerical aperture and acceptance angle of an optical fiber whose
core has a refractive index of 1.5 (refractive index of cladding = 1.447 and refractive
index of air =1)
(ii) What is the principle of fiber optics?
(iii) Explain the various types of optical fibers.
14. (a) (i) Explain Planck’s hypothesis.
(ii) State and derive Planck’s law of radiation
OR
(b) (i) Derive Schrodinger’s time dependent and time independent wave
equations.
(ii) Give the physical significance of wave function .
15. (a) (i) what is packing factor? Prove that the packing factor of HCP crystal is
0.74.
(ii) Explain the crystal structure of NaCl, ZnS, Diamond and Graphite.
OR
(b) Explain in detail the crystal defects and their types.
J 3918
B.E./B.Tech. DEGREE EXAMINATION, MAY/JUNE 2009
Second Semester
Civil Engineering
PH 2161 – ENGINEERING PHYSICS – II
(Common to all branches B.E./B.Tech.)
(Regulation 2008)
Time: Three hours
Maximum : 100 marks
Answer ALL questions
PART A – (10 X 2 = 20 marks)
1. Define the terms
(a). Relaxation time and
(b) Mobility.
2. What are the main drawbacks of classical free electron throe of metals?
3. What is meant by Fermi energy? What is physical significance?
4. What is meant by Hall Effect? Write an expression for the Hall coefficient.
5. Distinguish between intrinsic and extrinsic semiconductors.
6. What do you understand by the terms “critical temperature” and “critical field”
of a superconductor?
7. Distinguish between soft and hard magnets.
8. Mention four types of Polarisation mechanisms that can take palace in the presence of an
electric field in dielectric materials.
9. What are shape memory alloys? What are their properties?
10. What are the applications of carbon nanotubes?
PART – B (5 X 16 marks)
11. (a).
(b).
(i). State the assumption of the classical free electron model.
(ii). Obtain an expression for the electrical conductivity of a metal on
the basis of classical free electron theory.
(iii). The mobility of electron in copper is 3 x 10-3 m2/Vs. Assuming e =
1.6 x 10-19 C and me = 9.1 x 10-31 kg. Calculate the mean free time.
Or
(i). Explain the meaning of ‘density of states’. Derive an expression
for the number of allowed states per unit volume of a solid.
(ii). Write an expression for the Fermi energy distribution function, fFD(e)
and discuss its behavior with change in temperature. Plot fFD(e) for
T=0 K, and T > 0 K
(4)
(8)
(4)
(8)
(8)
12. (a).
(i).
Describe the energy band theory of solids with the help of neat band
diagrams. Distinguish between metals, insulators and semiconductors
on the basis of band theory. State the assumption of the classical free
electron model.
(8)
(ii). Derive an expression for the charge density in terms of Hall voltage
and further explain how the mobility of the charge carriers can be
evaluated by knowing the conductivity.
(8)
Or
(b).
13.
(a).
(i). Derive an expression for the electrical conductivity of an intrinsic
semiconductor.
(8)
(ii). The electron mobility and hole mobility in silicon are 0.135 m2/Vs and
0.48 m2/Vs respectively at room temperature. If the carrier concentration
is 1.5 x 1016 m-3 , calculate the resistivity of silicon at room temperature (4)
(iii). A sample of silicon doped with 1023 phosphorous atoms / m3. Find the
Hall voltage in a sample with thickness = 100 μm, current Ix = 1 mA
and magnetic field Bz=0.1 Wb/m2. (Assume electron mobility,
μe = 0.07 m3/Vs)
(4)
(i). Distinguish between Type I and Type II superconductors.
(ii). What are cooper pairs? Give an outline of BCS theory of
Superconductivity.
(iii). Write a short notes on SQUIDs.
(4)
(8)
(4)
Or
14.
(b).
(i). Give the classification of magnetic materials on the basis of magnetic
susceptibility. Briefly discuss the domain theory of ferromagnetism. (8)
(ii). Calculate the energy loss per hour in the iron core of a transformer,
if the area of the B-H loop is 250 J/m3 and the frequency of the
alternating current is 50 Hz. The density of the iron core is 7.5 x 103
kg/m3 and mass of the core is 10 kg.
(4)
(iii). A magnetic field of 2000 A/m is applied to a material which has
susceptibility of 1000. Calculate the
(1). Intensity of magnetization and
(2). Flux density
(4)
(a).
(i). Derive an expression for the internal field in a dielectric solids material. (8)
(ii). The dielectric constant of a helium gas at NTP is 1.0000684. Calculate the
electronic Polarisability of He atoms if the gas contains 2.7x 10 25
atoms /m3 and hence evaluate the radius of the helium atom.
(ε0 = 8.85 x 10-12 F/m)
(4)
(iii). Calculate the Polarisation produced in a dielectric medium of dielectric
constant 6 when it is subjected to an electric filed of 100 V/m.
(ε0 = 8.85 x 10-12 F/m)
(4)
Or
(b).
(i). what are Ferroelectricity ? explain the hysteresis curve exhibited by the
ferroelectric material with a suitable sketch. Give examples for
ferroelectric materials.
(8)
(ii). A capacitor consists of two conducting paltes of area 200 cm2 each
separated by a dielectric constant, ε = 3.7 of thickness 1 mm. find the
capacitance and the electric flux density when a potential of 300 V
is applied. (ε0 = 8.85 x 10-12 F/m)
(4)
(iii). Write short notes on uses of dielectric materials.
(4)
15.
(a).
(i). what are nanotubes? Describe their synthesis and properties.
(ii). Write a short note on pulsed laser deposition.
(8)
(8)
Or
(b).
(i). Describe the preparation and properties of metallic glasses.
(ii). Write short note notes on nanoparticles and their applications.
**************
(8)
(8)