Download BPUT QUESTION BANK FOR 4th SEM STUDENTS OF CS1, CS2

BPUT QUESTION BANK FOR 4th SEM STUDENTS OF CS1, CS2, EE&IT2007 BATCH, SESSION-2008-09 SUBJECT-PHYSICS-II, UNIT-I (NUCLEAR
ACCELERATOR)
SHORT QUESTIONS OF (2 MARKS)
1. A charged particle is accelerated in a cyclotron. Write the expression
for maximum kinetic energy of a particle in terms of its charge &
mass.
2. What is the ratio of the lengths of the adjacent tubes in a linear
accelerator?
3. The speed of a charged particle in a first drift tube of a linear
accelerator is 3 cm/sec.what is the speed of the particle when it is in
the second &third tube?
4. What happened to the output voltage of the voltage multiplier circuit
used in Cock-croft Walton accelerator if the capacitors used have
low capacitance?
5. What is the function of a cyclotron?
6. What is the function of a betatron?
7. Draw the schematic diagram of a betatron.
8. Write two medical applications of radioisotopes.
9. What is the literature meaning of the word “tandem”?
10. Nuclear particles obtained from nuclear accelerators are preffered to
the particle directly emitted from radioactive nucleai, for study of
nuclear reactions. Give two reasons substantiating the assertion.
11. What is the function of the magnetic field in a cyclotron?
12. How does the magnetic field in a betatron differ from the magnetic
field in cyclotron?
13. Why is the cyclotron not suitable for accelerating electrons?
14. The maximum energy acquired by an ion in a cyclotron is 3MeV.if the
frequency of r.f oscillator is doubled, other parameter remaining the
same, what would be the maximum attainable energy of the ion?
15. What is the maximum kinetic energy of a given type of ion
accelerated by a cyclotron change if the magnitude of the magnetic
induction is doubled?
16. Mention two practical limitations of Van de Graff accelerator.
17. Draw the graph showing the variation of output energy with number
of drift tubes in a linear accelerator?
18. ) Mention any three applications of radioisotopes.
19. One of the oldest linear accelerator at Berkeley has 46 tubes .If the
shortest tube is 1.2 meters what will be the length of the longest
tube?
20. Under what condition a charge particle can not accelerate by using
magnetic field.
21. A proton is revolving in a circular orbit of radius 100 cm under the
action of magnetic field induction 1 Tesla. What is the angle between
the plane of the circular orbit &magnetic induction?
22. Write in one sentence the necessity of nuclear accelerators.
23. A helium nuclei He42 nucleus is to be used as a projectile in some
atom smashing experiment for which negatively & slightly ionized
helium ion is accelerated by using tandem accelerator working under
a potential difference of 5x105 volt. Assume that all the electrons
were stripped off from the helium ion while passing through the
stripper. Calculate the final energy of the helium nucleus.
24. The applied magnetic induction in a cyclotron is 1.5T.Calculate the
frequency of RF voltage source used to accelerate protons.
25. Name the nuclear accelerator in which the charge particle is
accelerated by using only electric field.
26. Name few radio frequency nuclear accelerators?
27. Protons in a cyclotron describe a circle of radius of 40cm just before
emerging from the dees. The frequency of the applied alternating
voltage is 15MHz.Neglecting relativistic effects; find out the speed of
a proton on emergence.
28. Which particles are accelerated in a betatron? What is the
approximate shape described by the particle inside it?
29. The speed of a charged particle in the first tube of a linear
accelerator is 1.0 cm/s.What is the speed of the particle when it is in
the fourth tube?
30. Mention the factors which force scientists to construct nuclear
particle colliders.
31. What are the basic components of a typical nuclear accelerator?
LONG QUESTIONS OF (5 MARKS)
1. What is the need for particle accelerator?
2. Give the construction of a betatron. Mention the functions of the nonuniform & time varying magnetic field.
3. Distinguish between d.c & r.f accelerators. Give one example of
each.
4. Draw a schematic diagram of a tandem accelerator. Justify its
nomenclature.
5. Describe the construction of a linear accelerator.
6. Give the principle and working of a betatron.
7. Write four applications of radioisotopes.
8. Explain the action of a cock-croft Walton accelerator.
9. What is the principle of a cyclotron? Describe its construction and
working.
10. What are the practical applications of nuclear accelerators?
11. Describe the construction of a linear accelerator. Show that the
velocities of the ion in the tubes are in the ratio 1: √2: √3…
12. Describe with necessary principle and working of a betatron.
Mention its relative advantages.
13. Distinguish between the principles of cyclotron and betatron.
14. Give the construction and working of a two-stage tandem
accelerator.
15. Mention four medical applications of radioisotopes.
16. Prove that the average energy obtainable from betatron is limited by
its radius and peak magnetic flux of the applied field.
17. Derive an expression for the average energy of an electron as it
comes out of betatron.
18. What are the advantages & disadvantages of drift tube linear
accelerators? Write expression for the length of the nth tube in terms
of the length of 1st tube.
19. Describe with necessary theory the working of a typical cyclotron.
20. What are the factors which compelled scientists to construct nuclear
accelerators?
21. Give few examples of applications of nuclear radiations obtained by
using nuclear accelerators in the processing of materials.
22. What are the basic principles on which nuclear accelerators are
based on?
23. Describe the construction of a drift tube linear accelerator. Derive an
expression for the length of the nth number tube.
24. Explain by giving examples, how nuclear radiation is useful in
medical science.
25. What do you mean by nuclear accelerator? Distinguish between D.C.
& r.f. accelerators. Give two examples from each.
26. Describe with necessary theory the working of a betatron.What are
its limitations?
BPUT QUESTION BANK FOR 4TH SEM STUDENTS OFCS1,CS2, EE&IT-2007
BATCH, SESSION-2008-09 SUBJECT-PHYSICS-II, UNIT-II
(CRYSTALLOGRAPHY)
SHORT QUESTIONS OF (2 MARKS)
1. Why visible light is unsuitable for diffraction by crystalline solids?
2. In a cubic structure, calculate the spacing between (III) planes when
the lattice parameter is 1.732A0.
3. If the intercepts are 3a, 4b&3c, find out the Miller indices of that
plane.
4. Write Bragg’s condition for crystal diffraction.
5. How are primitive cell & unit cell of a crystal lattice related?
6. Define form factor.
7. The crystallographic axes in a cubic crystal are along X-, Y- & Z-axis.
What are the Miller indices of the plane parallel to the ZX plane?
8. Which factor determines the intensity of a scattered beam satisfying
Bragg’s law in crystal diffraction?
9. Explain why visible light cannot be used for study of crystal
structure?
10. Write Laue conditions for crystal diffraction.
11. State Bragg’s law for crystal diffraction.
12. Write Miller indices of a plane, in a, cubic crystal which makes equal
intercepts on the crystallographic axes.
13. Distinguish between primitive unit cell & unit cell.
14. Show the (110) plane of an orthogonal unit cell in a diagram.
15. If 0.1, 0.2, 0.3 are the co-ordinates of a point on a line passing
through an origin, determine the direction indices of the line.
16. What do u mean by planar density of atoms?
17. The lattice constant of a cubic crystal is 3.50A0.Calculate the interplanar spacing of (111).
18. What do u mean by a crystal?
19. Write the Miller indices of a plane in a cubic crystal, which makes
equal intercepts on the crystal axes.
20. Calculate the geometrical structure factor of a primitive unit cell.
21. The interplanar spacing in certain crystal is 3.4 Å. The first order
maximum occurs at diffraction angle 20˚. Find the wavelength of the
incident radiaton.
LONG QUESTIONS OF (CRYSTALLOGRAPHY)(5 MARKS)
Explain the assignment of Miller indices for a plane.
Derive Bragg’s law.
What is meant by reciprocal lattice?
Mention Laue condition for crystal diffraction. Show that Bragg’s
conditions follow from them.
5. Show that the dot product of a lattice translation vector & a
reciprocal lattice vector of a crystal is integral multiple of 2π.
6. Derive Bragg’s condition from Laue conditions in X-ray diffraction.
7. For a given family of planes in a crystal can the wavelength of
incident x-rays (a) too large (b) too small to form a diffracted beam.
Explain in detail.
8. What is the significance of Miller indices? How Miller indices are
found out?
9. A crystal plane cuts the crystallographic axes at 2, 3, 5 units
respectively. Find its Miller indices.
10. What is the need of reciprocal lattice concept? Derive a
relation between reciprocal lattice & direct lattice.
11. How is Miller indices assigned to crystal plane? A crystal plane
intercepts the crystallographic axes at 3, 2, 5 units respectively. Find
the Miller indices of the plane.
12. The lattice parameters of a cubic crystal are a=i, b=j-i, c=2i+k. Find
the reciprocal lattice vector A.
1.
2.
3.
4.
13. In an orthogonal lattice the primitive lattice vectors are given by a=i,
b=2j, c=k. Find the reciprocal lattice vectors.
14. Show that in a simple cubic lattice, interplanar spacing of (101) (110)
(011) planes are in the ratio 1:1:1.
15. Calculate the structure factor in case of body centered unit cell.
16. A crystal plane makes intercepts 2.93mm, 4.47mm and 2.35mm along
three crystallographic axes having lengths 3.05A0, 6.99A0&4.90A0
respectively. Determine the Miller indices of the plane.
17. Define reciprocal lattice with properties.
18. During study of a crystal, the 1st order X-ray diffraction is observed at
a diffraction angle of 450 with the characteristic X-ray wave length
1.54A0.Calculate the interplanar spacing of the crystal.
19. What are the characteristic features of Bragg’s law?
20. If 0.1, 0.2, 0.3 are the co-ordinates of a point on a line passing
through a origin, determine the direction indices of the line.
21. Calculate the structure factor in case of face centered cubic (FCC)
unit cell containing same type of atoms.
22. A beam of X-rays of wave length 1.54A0 incident at an angle 150
when the 1st order Bragg’s reflection occurs from (111) planes.
Calculate the inter atomic spacing.
23. Derive the Bragg’s law of X-ray diffraction .What are the differences
between X-ray diffraction and reflection of visible light by mirrors?
24. Derive the Laue conditions for X-ray diffraction.
25. Derive the Bragg’s law of x-ray diffraction. What are the difference
between x-ray diffraction by crystals & reflection of visible light by
mirrors?
26. Prove that every reciprocal lattice vector is normal to certain crystal
plane in direct lattice.
27. Define atomic form factor, scattering amplitude & geometrical
structure factor.Give their significance.
2007 BATCH, SESSION-2008-09 SUBJECT-PHYSICS-II, UNIT-III
(Semiconductor Superconductor)
SHORT QUESTIONS OF (2 MARKS)
1) Define forbidden gap.
2) Between insulator & semiconductor which has greater forbidden gap?
3) What is meant by compound semiconductor?
4) What is the difference between a semiconductor and a good conductor?
5) What is Meissner effect?
6) How according to Kronig-Penny model, does the width of forbidden
energy gap in solid changes as the energy increases?
7) In a fermionic system in the ground state, what is the probability of any
particle having energy greater than the Fermi energy?
8) How does the transition temperature of a superconductor depend on the
isotopic mass?
9) What is Meissner effect in superconductors?
10) Can a good conductor become a superconductor?
11) Give few examples of compound semiconductor.
12) What is the significance of Meissner effect in superconductivity?
13) What is Fermi level? Show the Fermi levels in a p-type & n-type
semiconductor in an energy level diagram.
14) Write the expression showing the temperature dependence of critical
magnetic field in a superconductor. Graphically show its variation.
15) Express the Fermi energy (Ef) of an intrinsic semiconductor at absolute
zero temperature, in terms of the energy (Ec) of the bottom of the
conduction band at the energy (Ev) of the valence band.
16) According to Kronig-Penny model, how does the width of allowed
energy bands in solid changes with increase of energy?
17) What is the value of magnetic susceptibility of a Type-I superconductor
below transition temperature?
18) Write down London equations mentioning the meaning of each symbol.
19) The ground state energy of hydrogen atom is 13.6eV.calculate the width
of 1st forbidden gap in hydrogen atom.
20) Why in p-type material the number of electrons in conduction band is
less than that of holes in valence band?
21) For the flow of electrons there must be a potential difference .Name the
phenomenon where the electrons can flow even though there is no
potential differential .Who discovered it first?
22) How superconductivity concepts helped US forces in2003 to destroy
Iraqi communication system?
23) Why Type-I superconductors are called soft superconductors?
24) The critical temperature of a superconducting specimen with isotopic
mass 196.5 is 4.18K.Calculate its critical temperature when its isotopic
mass changes to 203.4.
25) At certain temperature the resistances of a wire become zero. Can we
call the wire a superconductor? Justify your answer.
26) Calculate the critical magnetic field for tin at 1.5K.The data given for tin
are Tc=3.72K, and Bc=30.5x10-3Tesla at 0K.
27) What is the role of donor atom in an extrinsic semiconductor?
28) Give the band diagram of semiconductor &insulators.
29) What type of temperature coefficient of resistance does a pure
semiconductor has?
30) In a particular material forbidden energy gap between conduction band
& valence band is of the order of 6eV.To which type of material does this
material belongs to electrically?
31) Write an expression for London’s penetration depth at any temperature.
32) What is cooper pair in superconductivity?
33) The critical temperature for mercury with isotopic mass 199.5amu is
4.18K. Calculate its critical temperature when its isotopic mass 203.4amu.
34) State Bloch’s theorem in one-dimension as applied to the periodic
potential of atomic lattice.
35) Ions are arranged linearly along x-axis in such a manner that the
distance between two consecutive ions is ‘a’. Define the one-dimensional
periodic potential for this arrangement of ions.
36) Give few examples of intrinsic & extrinsic semi conducting materials.
37) Show graphically the variation of resistance of a normal conductor with
absolute temp.
38) Draw the band diagram of conductor, insulator & semiconductor.
39. What is the basic physical principle responsible for the presence of
energy bands rather than specific energy levels in a solid?
40. In a fermionic system in the ground state, what is the probability of any
particle having energy less than the Fermi energy?
41. Mention few properties of Cooper pair.
LONG QUESTIONS OF(Semiconductor Superconductor) (5 MARKS)
1)
2)
3)
4)
5)
6)
7)
8)
9)
Distinguish between semiconductor, conductor & insulator.
Give an idea about Kronig-Penny model.
Give few properties of superconductors.
Write few applications of superconductors.
Write the potential is used in Kronig penny model. Give its graphical
sketch.
Write the Fermi distribution function& mention the symbols used.
Mention with appropriate diagram the position of Fermi level in
intrinsic & extrinsic (both donor & accepter) semiconductors at room
temperature.
What is critical field in a superconductor? Graphically show its
variation with increase in temperature from absolute zero up to the
transition temperature.
Graphically show the variation of magnetization in Type-I & Type-II
superconductors.
10) Write the expression for London’s penetration depth. How does it
depend on temperature?
11) Write any three applications of superconductors.
12) Distinguish between Type-I & Type-II superconductors.
13) Write down London equations for super current density. Mention the
symbols used.
14) Mention six commercial applications of superconductivity.
15) What is Meissner effect? Classify superconductors on the basis of
Meissner effect.
16) Write the expression for change of entropy when a system
undergoes phase transition from normal to super conducting state.
Graphically show the variation of entropy with temperature for both
normal to super conducting state.
17) What is Fermi energy? Show in energy band diagram the position of
the Fermi levels in intrinsic, p-type & n-type semiconductor at absolute
zero temperature.
18) Distinguish between a perfect conductor and superconductor.
19) What are the inferences do you obtain from Kronig-Penny model.
20) Explain on the basis of BCS theory how superconductivity is
affected by temperatures.
21) Explain the origin of semiconducting properties in compound
semiconductors.
22) Derive an expression for the energy of an electron inside an infinite
potential well from Kronig penny model.
23) How superconductors can be used in internet & pollution control?
24) Distinguish between compound semiconductor&elemental
semiconductor. What are the advantages of compound semiconductors
over elemental semiconductors?
25) The London’s penetration depth for lead at 3K is 396A0 and at 7.1K is
1730A0.Calculate its critical temperature and penetration depth at 0K.
26) Distinguish between single mode optical fibre and multi mode
optical fibre.
27) Explain the origin of energy bands quantum mechanically.
28) How superconductivity concepts find wide applications in the field
of defence and pollution hazards?
29) Let the electrons be ideally bound to the atoms as in case of
infinitely deep potential well .using Kronig-Penny model derive an
expression for the energy of an electron moving in the periodic
potential.
30) What are the differences between p-type & n-type semiconductors?
31) Derive London equations in superconductivity.
32) Plot the dispersion curve (E vs k=2π/ λ) of an electron moving in a
one dimensional periodic potential. What are the inferences you draw
from this plot regarding the band concepts of substances?
33) How superconductivity concepts have been exploited in the
following technologically in the following fields:
1) Surface transportation
2) Health science
3) Distribution of electric power
4) Defence.
34) Give an idea about Kronig –penny model.
35) What do you mean by compound semiconductor .Give few
examples?
36) Write the expressions for critical magnetic field & critical current
density in superconducting phenomenon.
37. Calculate the London penetration depth at 2.5 K in superconducting
state of a material from the following data.Tc =5.7K, density=7.3 g/cm3,
atomic mass =118.7 amu, effective mass of electron =17.29 x10-31 Kg.
38. Explain how Kronig-Penney model predicts the presence of allowed
& forbidden energy bands in crystals.
39. Mention at least 10 numbers of modern applications of the
superconductivity phenomenon.
BPUT QUESTION BANK FOR 4THSEM STUDENTS OF CS1, CS2, EE&IT2007 BATCH, SESSION-2008-09 SUBJECT-PHYSICS-II, UNIT-IV
(Laser.LED&Fibre optics)
SHORT QUESTIONS OF (2 MARKS)
1) What is the full form of LASER?
2) What is meant by coherence length?
3) Name the three component of optical fibre.
4) Write about two applications of fibre optics.
5) A system is in thermal equilibrium under normal conditions. Which
type of emission is the dominating process, spontaneous or
induced?
6) The refractive indices of the core and cladding material of an optical
fibre are n1&n2 respectively. What is the numerical aperture the
fibre?
7) Draw the refractive index profile of a step index optical fibre.
8) What is the difference between laser light & ordinary light?
9) What is the basic phenomenon exploited technologically in optical
fibre communication.
10) Mention two applications of LASER.
11) Determine the wave length (λ) emitted by an atom due to
transmission from an excited level E2 to the ground state with energy E1,
if E2-E1=2.46eV.
12) Why is population inversion referred to as” negative temperature”?
13Find out ‘coherence length’ in a laser beam for which the coherence
time is .5ns.
14) What is graded index optical fibre? Draw the refractive index profile.
15) Determine the acceptance angle for an optical fibre having core &
cladding refractive indices 1.58 &1.48 respectively.
16) Mention the merits of semiconductor laser.
17) What is lasing threshold of a laser?
18) Draw the refractive index profile of a graded index optical fibre.
19) Why population inversion is not possible for direct transition
between two energy levels?
20) Why light beam traveling in optical fibres can carry much more
information than a radio or micro-waves?
21) What is the difference between LED&LD?
22) Distinguish between step index &graded index multiple mode optical
fibre.
23) What is the color of the light coming from ruby laser? Why its color
is so?
24) Distinguish between spontaneous emission and simulated emission.
25) What are the different types of electronic transitions occur when
electromagnetic radiation of suitable frequencies is incident on the
material?
26) Show graphically the variation of refractive index of core of a graded
index optical fibre with respect to radius of core.
27) Show in a figure, the different parts of an optical fibre.
28) A laser beam of wave length 6800A0 has coherence time 4.5x10-5sec.
Determine the temporal coherence length, spectral width and purity
factor.
29) The refractive indices an optical fibre are 1.3725&1.3275
respectively. What is the numerical aperture the fibre?
30) The working principle of a device was outlined by two American
physicists Arthur Schawlow & Charles Hard Townes in their 1958 patent
application. What is that device?
31. What are different types of electronic transitions occur when
electromagnetic radiation of suitable frequencies is incident on the
materials?
32. What is difference between laser light & ordinary light?
33. Draw the refractive index profile of a graded index optical fiber.
LONG QUESTIONS OF (Laser.LED&Fibre optics)(5 MARKS)
1) What are the basic characteristics of optical fibres?
2) Distinguish between spontaneous and stimulated emission of radiation.
3) What is population inversion? Why a system with population inversion
is said to have negative temperature?
4) What is graded index fibre? Show the optical path of a ray in such a
fibre.
5) Describe the construction & working of a semiconductor laser.
6) Why is a metastable level between stable energy levels necessary for
laser emission?
7) Why is a system with four allowed energy levels more suitable than a
three level system for laser action?
8) Why is ’optical feed back’ necessary for laser device? How is it
achieved?
9) Draw the block diagram of a FOCL and explain the working of each
section, mention its advantages.
10) Distinguish between active optical fibre sensor & passive optical fibre.
Mention some of their uses.
11) Describe the basic structure of a semiconductor laser and explain its
working.
12) What is population inversion? Discuss the role of met stable state in
achieving population inversion.
13) Give the construction, working & uses of a LED.
14) Describe how optical fibres are in use to enhance the living conditions
on earth.
15) Describe different types of pumping mechanisms to achieve population
inversion.
16) What are the characteristics of an optical sources used in FOCL?
17) What is pumping? Mention different methods to achieve population
inversion.
18) How optical fibres are helpful to doctors in medical fields?
19) What is the principle of semiconductor laser? Write few applications of
diode laser.
20) What are the advantages of optic communication system over
traditional copper cable communication system?
21) What is light emitting diode? What are different mechanisms
responsible for emission of light in LED?
22) Describe the construction of a typical laser.
23) The refractive indices of core & cladding of a step index fiber are 1.48 &
1.47 respectively. The core radius is 25 μm. Assume the guided ray is
traveling at steepest angle with respect to fiber axis. Calculate the
number of reflections per meter.
24) Give the construction & working of LED. What are the merits of LED
over incandescent lamp?
25) Draw the block diagram of a FOCL & explain the working of each
section.
1ST QUESTION BANK FOR PHYSICS-I(UNIT-I&UNIT-II)
For Sec-B1, B2&B3, Batch-2008.
(All the questions are from BPUT sets of questions2003 to 2008)
SHORT QUESTIONS
1. Two sinusoidal waves of same frequency and having amplitudes
A1 &A2 respectively superpose coherently. Write the expression
for the maximum and minimum values of the intensity of the
resultant wave.
2. Two simple pendulums of mass ‘M’ in and length ‘L’ each are
coupled by a spring of farce constant K. Write the expression for
angular frequency of normal modes of vibration of the coupled
system
3. In a Newton’s tings experiment the diameter of bright rings are
proportional to the square root of natural numbers. Are the rings
formed by reflected light? Explain.
4. A uniform string of length 2 meter and mass 200 Gms is under a
tension of 800N. Calculate the speed of transverse wave in the
string.
5. The radii of the 10th and 50th rings in the Newton ring experiment
are 0.2cm. And 0.8cm respectively. Find out the wavelength of the
light of the radius of curvature of the convex surface of the Plano
convex lens is 100cm.
6. A wave packet propagates in a medium which exhibits normal
dispersion write the relation between phase velocity and group
velocity which is greater and why?
7. A Uniform string S1 is connected with another uniform string S2
whose linear mass density is greater than that of S 1 A wave pulse
propagating alone one string meets the another at a junction where
a part is transmitted and apart is reflected back as shown in fig
In which string did the wave propagates initially? Explain.
8. A progressive sinusoidal wave is represented by y (x,t)=A sin
[(0.2m1) x- (0.45) t+ π/6]
Where ‘x’ and‘t’ are in meter and second respectively. Determine the
speed of propagation of the wave.
9. Mention the conditions for production of a sustained interference
pattern.
10. A forced oscillator is at resonance with the external periodic force
what is the phase difference between the driving force and the
velocity of the oscillator?
11. In a stationary wave the wavelength is 3.6m. What is the distance
between a node and nearest anti-node?
12. In a young’s double slit arrangement the separation between the
two slits is reduced to half of its original value how will the fringe
width be affected?
13. Mention the characteristics of wave motion.
14. Identify the terms in the wave function given by
Ψ(r, t) =A sin (k.r –wt +Φ)
15. Displacement associated with a wave is given by
Y (x, t) = 0.1 cos (0.2x-2t) Where X and Y are given in terms of cm and‘t’
is in second calculate the wavelength amplitude frequency and
velocity.
16. Calculate the speed of longitudinal wave at NTP. (Given density of
air at NTP is 1.3x10-3 gm/cm and Cp/Cv = 1.4)
17. In young’s double slit experiment the distance between two slits is
0.5 mm. If the wavelength of light used λ= 5 x 10-5 cm and distance
of the screen for the slit D= 50 cm Calculate the fringe-width.
18. Explain why a narrow slit is used in case of biprism experiment
where as an extended soirée in used in Newton’s Ring experiment.
19. A vertical spring executes S.H.M.with a period of 1 sec. When a
mass of one gram is suspended at the lower and of the spring find
the length through which the spring is stretched.
20. In a Newton Ring experiment the diameter of nth and (n+8) th bright
rings are 4.6 mm and 7.4 mm respectively the radius of curvature of
the lower surface of the lens is 2m. Determine the wavelength of
the light.
21. The natural angular frequency of a simple harmonic oscillator of
mass 2gram is 0.8 rad/secs. It undergoes critically damped motion
whew taken to a viscous medium. Find out the damping force on
the oscillator whew its speed is 0.2 cm/sec.
22. Twenty sinusoidal waves of equal amplitudes superpose
incoherently to produce. A resultant wave of intensity 0.5 watt /m2
what would be the resultant intensity if the waves superpose
coherently?
23. In a Newton’s ring experiment performed in air, the diameter of a
given ring is 0.2mm when a liquid is introduced between the lens
and the plane glass plate below it the diameter of the ring shrinks
to 0.17mm. Find the refractive index of the liquid.
24. Write the wave equation for a one dimensional wave propagating
along the (+) ve Y-axis in an elastic medium of density (ƒ) and bulk
modulus B.
25. Find out the speed of longitudinal wave propagating in a medium of
density p = 6x103 Kg/m3 and bulk modulus B = 1.2 x 108 N/m2.
26. In a Newton‘s ring system the center is bright. Is the ring system
observed in reflected or transmitted light? Justify your answer.
27. In young’s double slit experiment. The screen is 1m away form the
slits. The separation between the slits is 1mm and the distance
between the 1st and 4th fringe is 1.2mm Determine the wavelength of
light used.
28. The displacement of a one- dimensional simple harmonies
oscillation of mass 5gms is Y (t) = 2 cos (0.6t + θ) where ‘Y’ and‘t’
ore in cm and second respire timely. Find the kinetic energy of the
oscillator.
29. In a damped oscillator, the damping force in proportional to the
velocity. Mention the positions at which the damping force
vanishes.
30. In a young’s double slit experiment. A point ‘p’ on the screens in
equidistant from both the slits. If any one of the slits is closed. The
intensity at ‘p’ due to the other slit in O.02 w/M2 what is the
intensity at ‘p’ when both the slit are open?
31. A plane monochromatic wave. Traveling in a homogeneous
medium. Meets a denser medium. What are the charges in (a)
amplitude (b) phase (c) speed of propagation (d) phase of the
reflected and transmitted waves in compromiser with
corresponding proportion of incident wave?
32. Two identical simple pendulums each of mass ‘m’ and length ‘L’
are coupled by a spring of farce constant K. Write the expression
for the normal mode frequencies of the coupled oscillatory system.
33. Draw a schematic diagram of the experimental arrangement to form
Newton’s rings.
34. In Young’s double slit experiment. The intensities on the screw due
to the individual slits are I1 and I2 respectively. What is the
difference between the maximum and minimum intensity in the
fringe pattern?
35. A monochromatic wave is represented by the wave function ψ (x1t)
= (8cm) sin (Пx- Пt/2) where ‘x’ is in cm and‘t’ is in second. Find the
amplitude. Frequency and wavelength of the wave.
36. The maximum amplitude of a forced damped oscillator is 2.5cm
what will be the maximum amplitude if the damping constant and
magnitude of the driving farce are doubled.
37. Two waves of same frequency have amplitudes 2units and 3 units
respectively. When they superpose coherently the intensity of the
resultant wave is I1. The intensity becomes I2 when they super pose
incoherently. Find the ratio I1/I2.
38. The Fringe width in a Young’s double slit arrangement is 0.008cm.
What would be the fringe width if the slit separation is halved and
the slit-screen distance is doubled?
39. Set up the differential equation for a damped oscillator subjected to
an external periodic force f0 Sinpt and damping force proportional
to the speed of the oscillator.
40. Evaluate the Q-factor of a damped oscillator with resonant
frequency 500Hz and damping coefficient 0.5 per second.
41. In a Newton’s ring arrangement the diameter of a bright ring is 0.5
cm. What would be the diameter of the ring if the lens placed on the
plane glass plate is replaced by another having doubled the radius
of curvature?
42. The differential equation of motion of a freely oscillating body is
d 2x
given by 2 2  18 2 x  0 . Calculate the natural frequency of the
dt
body.
43. One-day Young’s double slit experiment was performed in Physics
laboratory by taking monochromatic blue, orange and red lights
and fringe widths were obtained as  B ,  C and R respectively. Other
variables had been constants. Write a relation between  B ,  C and R .
44. What is the physical significance of a damping co-efficient? What is
its unit?
45. Two simple harmonic oscillators of masses 10 gm and 800 gm
oscillate separately under the action of same restoring force.
Calculate the ratio of their frequencies.
46. Why very narrow slits are taken in Young’s double slit interference
experiment?
What is the condition for the destructive interference in terms of
phase difference between the two interfering waves?
47. The total energy of a one-dimensional simple harmonic oscillator is
0.8 ergs. What is its kinetic energy when it is midway between the
mean position and an extreme position?
48. The amplitude of a forced damped oscillator is 1.2 cm. What would
be its amplitude if the magnitude of the driving force is doubled?
49. In a Newton’s ring set up, the gap between the lens and the glass
plate is filled with a transparent liquid. If the liquid is replaced by a
second liquid the ring shrinks. Which of the two liquids has greater
refractive index and why?
50. A plane monochromatic wave propagating in a homogeneous
medium meets another homogeneous medium (where density is
more) How do the frequency, wavelength and speed of propagation
of the wave change in the second medium?
51. Two identical strings M and N hang from a ceiling masses of 5 kg
and 10 kg hang from M and N respectively. Find the ratio of the
speed of propagation of transverse wave in M to that in N.
52. In a Young’s double slit interference pattern the fringe width is
0.1mm. What would be the fringe width if the wavelength of light is
reduced by 10% and the distance between the source and the
screen is increased by 10%?
53. In a Young’s double slit pattern the wavelength of light from the
sources is 5000 A0. At a given point on the screen the path
difference between the waves from the two slits is 20000 A0. Find
whether a dark or bright fringe is produced at the point.
54. Two waves having same frequency traveling in opposite direction
are superposed to produce a resultant wave. Mention two basic
terms connected with its resultant wave.
55. Optical interference phenomenon is broadly divided into two
categories namely (a) division of waveform (b) division of
amplitude. Mention one example for each category of interference.
56. The equation of a stationary wave in a medium is given
2x
sin 10t . Here Ψ and x are in cm and‘t’ in seconds.
by  4 cos
13
Calculate the amplitude, wavelength of the two component waves.
57. What is the condition for the destructive interference in terms of
phase difference between two interfering waves?
58. How many times the potential energy and kinetic energy of a simple
harmonic oscillator attains maximum value in one complete
oscillation?
59. Young’s double slit experiment was specially modified to observe
fringe pattern looking vertically downward perpendicular to the
optical bench (instead of looking along the optical bench).What
type of fringe pattern will be observed?
60. What does happen to phase of sound wave as it comes from water
to air medium?
61. The forced harmonic oscillations have same displacement
amplitudes at the frequencies w1=400/sec& w2=800/sec. Calculate
the resonant frequency at which the displacement is maximum.
62. Show graphically the variation of the fringe width with the distance
between the two coherent sources in Young’s double slit
experiment.
63. What is linear frequency of a simple harmonic oscillator described
by the equation X=sin (12.56t) where instantaneous position ‘X’ is
measured in meter and time is measured in seconds.
64. What is the colour of the central fringe in Newton’s ring experiment
as seen by transmitted monochromatic light when the space
between curved surface of the Plano convex lens and plane glass
plate contains ethyl alcohol?
65. A forced harmonic oscillator is at resonance with certain periodic
force. What is the phase difference between the driving force & the
velocity of the oscillator?
66. In a Young’s double slit interference pattern the fringe width is
.1mm. What would be the fringe width if the wavelength of light is
increased by 10% and the distance between the source & screen is
reduced by 10% keeping other factors constant?
67. Show in a single plot, the time variation of amplitudes of an over
damped harmonic oscillator and critically damped harmonic
oscillator under identical conditions.
68. In a Newton’s ring arrangement the diameters of the 5th & 10th dark
rings are 0.122cm&.150cms respectively. What is the diameter of
the 15th dark ring?
69. Find the speed of longitudinal wave propagating in a medium of
density 6x103 kg/m3 & bulk modulus 1.2 x 108 N/m2.
70. Why very narrow slits are taken in Young’s double slit interference
experiment?
71. In a Newton’s ring arrangement, the diameter of a bright ring is 0.5
cm. What will be the diameter of the ring if the lens placed on the
plane glass plate is replaced by another one having double the
radius of curvature?
LONG QUESTIONS
1. A damped oscillator is subjected to a damping force proportional to
its velocity. Set up the differential equation of the oscillator. Discuss
the under damped, over damped and critically damped motions of
the oscillator.
2. An oscillator is subjected to an external sinusoidal periodic force
and a damping force proportional to its velocity. Setup a differential
equation of the oscillator. Mention the condition under which
velocity resonance occurs.
3. Graphically show the displacement time curve for oscillatory over
damped and critically damped motion of a damped oscillator.
Mention the condition of their occurrence.
4. With the help of a suitable ray diagram. Describe the production of
Newton’s rings.
5. Two sinusoidal waves of same amplitude and frequency superpose
to produce a resultant wave whose completed is the same as that of
each of the individual waves. Find the phase difference between the
individual waves.
6. Why does a soap bubble appear colored when seen under sunlight?
What happens when the thickness of the bubble becomes extremely
small?
7. Explain how the wavelength of monochromatic light is determined
using Newton’s ring arrangement.
8. Set up the differential equation for a simple harmonic oscillator
subjected to an external sinusoidal periodic force and a damping
force proportional to its velocity of the oscillator and a periodic force
of angular frequency ‘W’.Obtain the most general solution and
discuss about resonance.
9. Mention the conditions necessary for production& observation of a
sustained interference pattern.
10. Two harmonic waves of the same amplitudes and frequency. But
different phase superpose. Obtain expression for amplitude and
phase of the resultant wave.
11. A plane monochromatic wave, traveling in a homogeneous medium,
meets a denser medium meets another medium. What are the
changes in (i) amplitude (ii) frequency (iii) speed of propagation &
(iv) phase of the reflected wave & transmitted waves in comparison
with the corresponding properties of the incident wave?
12. Two harmonic waves of the same amplitude. Frequency and
wavelength travel in a medium a long the (time) and (-ve) Y-axes
respectively. Find the positions where nodes and anti-nodes are
formed.
13. Distinguish between stationary and progressive waves. Find out the
phase difference between two adjacent nodes in standing wave.
14. Mention the conditions needed for production of a sustained
interference patterns.
15. Derive an expression for the amplitude of an under damped
harmonic oscillator during nth number oscillation.
16. Show what in normal mode of higher frequency two masses of the
coupled oscillator are out of phase.
17. In a Newton’s ring experiment in laboratory the light having two
wavelengths 6000A0and 4500A0is used .It is found that nth dark ring
due to 6000A0coincides with (n+1)th .Calculate the radii of nth dark
ring due to 6000A0and 4500A0 if radius of curvature of the Plano
convex lens is 100cm.
18. Derive an expression for the amplitude of an under damped
harmonic oscillator during nth number oscillation.
19. What is meant by coupled oscillation? Show that in normal mode of
higher frequency two of coupled oscillators are out of phase.
20. Prove analytically that the shapes of the interference fringes
obtained in young’s double slit experiment are by hyperbolic.
21. Describe with neat diagram the formation of Newton rings.
22. The forced harmonic oscillations have same displacement
amplitudes at the frequencies w1=400/sec& w2=800/sec. Calculate
the resonant frequency at which the displacement is maximum.
23. Show mathematically that the total energy of a simple harmonic
oscillator remains constant.
24. Find out the reflection and transmission Co-efficient for a wave at the
boundary of 2 media.
25. Give few applications of coupled oscillator concepts.
26. A Plano – convenes lens of radius of curvature 2.5 mts is placed on
an optically plane glass plate in air medium and a parallel beams of
monochromatic light is incident normally on the set up to observe
the Newton’s rings The diameter of the 5th bright ring as seen by the
reflected light is 0.70cm.Calculate the wavelength of the light used.
27. Show graphically the variation of completed of an under damped
harmonic oscillator with time and explain the nature.
28. Write down the equations describing under damped, over damped &
critically damped one dimensional harmonic oscillator.
29. What the conditions are for to obtain interference pattern having a
good contrast in Young’s double slit experiment.
30. The time period of simple harmonic oscillator is 4s.It is subjected to
a damping force proportional to its speed with damping coefficient
0.1/sec. Find the time period & logarithmic decrement when simple
harmonic oscillator was subjected to the damping force.
31. A plano-convex lens of radius of curvature 2.5m is placed on an
optically plane glass plate in air medium & a parallel beam of
monochromatic light is incident normally on the setup to observe the
Newton’s rings. The diameter of the 5th bright ring as seen by the
refracted light is 0.75 cm. Calculate the wavelength of the light used.
32. An oscillator is subjected to an external sinusoidal periodic force &
damping force proportional to its velocity. Set up a differential
equation for the oscillator. Mention the conditions under which
velocity resonance occurs.
2ND QUESTION BANK FOR PHYSICS-I(UNIT-III&UNIT-IV)
Sec-B1, B2&B3, Batch-2008.
(All the questions are from BPUT sets of questions2003 to 2008)
SHORT QUESTIONS
1. A monochromatic beam of light is split in to ordinary and extraordinary rays and it is incident on a half wave plate. How much
additional phase difference between the ordinary and extra-ordinary
ray is introduced by the half wave plate?
2. The 2nd order maximum for a wavelength of 6360 A0 in a transmission
grating coincides with 3rd order maximum of am unknown light
Determine the wavelength of the unknown light.
3. A narrow slit. Illuminated by monochromatic light produces
Fraunhoffer diffraction. Graphically show the intensity distribution in
the diffraction pattern. Write the expression for intensity distribution.
4. A mica sheet of thickness ‘L’ is used as a quarter wave plate for light
of wavelength Express the difference between the refractive indices
of mica for ordinary rays.
5. Distinguish between Fresnel and Fraunhoffer diffraction.
6. A transmission grating has 8000 rulings per cm. the first order
principal maxima due to a monochromatic source of light oceans at
an angle of 300 Determine the wavelength of light.
7. The brightest image due to a zone plate is formed at a distance of
15cm form it. At what distance from the zone plate will the next
bright image be formed?
8. What is the angle between the plane of polarization & the plane of
vibration in a plane polarized beam?
9. Give the pictorial representation of the end-on-view of Un-polarized
and plane polarized light.
10. A light beam passes thought a Nicol Prism. The emergent light
doesn’t show any variation in intensity as the Nicol is rotated. What
would you conclude about the state of polarization of the incident
light?
11. A monochromatic light of wavelength 6000Aºis incident on a plane
diffraction grating with a grating element 6.0x10-5cm. What is the
maximum order of spectrum that can be observed?
12. A Zone plate is to have a principal focal length of 50cm
corresponding to wavelength 6.0x10-5cm.obtain values of radii of
different Zones.
13. Calculate the Brewster’s angle for a glass slab (n=1.5) immersed in
water (n=1.33).
14. A beam of light of wavelength 5000Aºis falling normally on a plane
diffraction grating. The 1st order spectrum is formed in a direction
making an angle…, with the normal (Sin…=.25). Calculate grating
element and angle …. For second order spectrum.
15. The primary focal length of a Fresnel zone plate is 8cm with
monochromatic red light (λ =6000A0.) what would be the focal length
if a monochromatic light with. λ =4800A0 is used?
16. A light beam is allowed to pass through a Nicol prism, as the prism
is rotated about an axis parallel to the incident beam the intensity of
the emergent beam undergoes variation and become zero at one
position what is the state of polarization of the incident light beam?
17. A plane diffraction grating of width 2.5cm has 12500 rulings on it
what is the maximum order of grating spectrum observable for
incident light of wavelength 5500A0?
18. In a Fraunhoffer diffraction due to single slit the 1st order minimum is
observed at angle 300 with the incident beam what is the width of the
if wavelength of incident light is 6000A0 ?
19. The refractive indices of a double refracting crystal for ordinary and
extra-ordinary rays are 1.584 and 1.592 respectively. For wavelength
5600A0. Determine the thickness of the crystal required to produce a
quarter wave plate.
20. In a plane transmission grating. The width of each slit is equal to half
of the width of the opaque portion. Which order of spectra will be
absent?
21. A beam of monochromatic light traveling in air is incident at the
polarizing angle on a glass slab. What is the angle between the part
of the beam reflected in to air and the part transmitted in to glass?
22. How can you distinguish between circularly polarized light and
unpolarized light?
23. 50 gm of an optically active substance is dissolved in 100ml of water.
A plane polarized light whew passing through 30cm of the solution
suffers a rotation of 390 in its plane of polarization. Find out the
specific rotation of the solution.
24. The brightest & image due to a Fresnel zone plate is formed at a
distance of 45cm form it. At what distance is the next bright image
formed?
25. A monochromatic beam of unpolarized light is incident on a glass
slab. The reflected ray is found to be completely plane polarized.
Determine the angle between the reflected ray and the refracted ray.
26. A beam of monochromatic light passes through a Nicol prism. The
emergent ray doesn’t show any variation of intensity when the Nicol
is rotated about an axis parallel to the incident beam. What would
you conclude about the stale of polarization? Of the incident beam?
27. Why diffraction can not occur if slit width is less than the wavelength
of the light.
28. The light passing through a quarter wave plate is analyzed by a
rotating Nicol prism. It is found that the intensity of emergent light
beam from the rotating Nicol prism beams maximum and minimum
equal to zero. What would we conclude state of polarization of the
incident light?
29. In a single slit diffraction intensity of the first secondary maximum is
less that of primary maximum by how many times?
30. The light is incident on a rotational Nicol prism and the intensity of
the emergent beam becomes maximum and zero periodically. What
we can conclude state of polarization of the incident light?
31. A sugar solution was prepared by adding 80gms of cane sugar in to
one litre of water. By observation it is found that it gave an optical
rotation of 9.90 when filled in a 20cms tube. If specific rotation of the
pure sugar is 66cm/gm.Find the percentage of purity of the sugar.
32. The area of the 1st half period zone in a Fresnel’s zone plate is
0.01mm2. What is the area of the 2nd half period zone?
33. A source of monochromatic light is viewed through a Nicol prism.
When the Nicol is rotated the intensity of light changes and the
source becomes invisible at a given position of the Nicol. What is the
stale of polarization of the light emitted by the source?
34. An optical instrument manufacturing unit asks you to construct a
quarter wave plate of mica to be used in connection with sodium
vapour lamp. The data given to you are
a) Wave length of sodium vapour lamp is 5890A0 .
b) Indices of refraction for ordinary and extra-ordinary rays
respectively.
35) A beam of monochromatic light when incident normally on
diffraction grating containing 3000 lines cm. the first order spectral line
is observed at angle 10.18. Calculate the wavelength of the mildly light.
36. The area of the 1st half – period zone is a Fresnel’s zone plate is 0.01
mm2 what is the area of the 2nd half period zone?
37. A source of monochromatic light is viewed through a Nicol prism.
When the Nicol is rotated. The intensity of light changes and the source
becomes invisible at a given position of Nicol. What is the state of
polarization of the light emitted by the source?
38. State & explain Brewster’s law.
39. Mention at least any two similarities between a zone plate& a convex
lens.
40. What is the maximum wavelength of visible spectrum so that 3rd
order spectrum can be observed by a plane diffraction grating having
5654lines/cm?
41. Mention at least any two differences between optical interference&
optical diffraction.
42. The plane of polarization of a plane polarized light is rotated through
an angle 200 while passing through 20cm in a sugar solution having
specific rotation 450cm2/gm. Calculate the concentration of the sugar
solution.
43. In a single slit diffraction pattern due to single slit the distance
between the 1st minimum on left to the 1st minimum on right is0.054cm
for a light of wavelength 5890A0. Calculate the slit width if the distance
of the screen from the single slit is 100cm.
44. How many orders of diffraction bands are visible theoretically if
wavelength of incident radiation is 5893A0 and the number of lines per
cm on the grating is 6000?
45. What is the difference between Fresnel’s 1st half period zone and
Fresnel’s 2nd half period zone as envisioned by him to explain the
optical diffraction phenomenon?
46. Out of ordinary and extra Ordinary rays of light which ray obeys
Snell’s law?
47. A light beam is allowed to pass through a Nicol prism.As the prism
is rotated about an axis parallel to the incident beam, the intensity of the
emergent beam undergoes variation & becomes zero at one position.
What is the state of polarization of the incident beam?
48. A narrow slit, illuminated by monochromatic light produces
Fraunhofer diffraction. Graphically show the intensity distribution of the
diffraction pattern.
LONG QUESTIONS
1. What is a zone plate? Explain the formation of images by a zone
plate. Compare its working with that of a converging lens.
2. State and explain Brewster’s law. Show that when light traveling in
one transparent medium meets another transparent medium at the
polarizing angle. The reflected and transmitted rays are
perpendicular to each other.
3. Bring out the similarities and differences between a zone plate and a
converging lens.
4. Distinguish among plane polarized. Circularly polarized and unpolarized light.
5. Describe the construction and working of a Nicol prism by giving
suitable principle.
6. Describe Brewster’s experiment and explain how Brewster’s law was
formulated?
7. Disuses how the wavelength of monochromatic light can be
determined by using a plane diffraction grating?
8. Explain the meaning of “missing spectra” in the diffraction patter a
plane transmission grating.
9. Obtain expression for intensity of the diffracted beam by a single slit.
Discuss the position of maxima and minima.
10. Describe how elliptically and circularly polarized light is generated?
Explain the process for realization of plane polarized light from
elliptically polarized light.
11. Give the construction of Nicol prism. Explain how it produces
polarized light.
12. What is double refraction? Differentiate between ordinary and extraordinary rays in a double refracting crystal.
13. Give the construction of a zone plate. How does the primary focal
length of a zone plate depends on the wavelength of light used?
14. The position of the wave front of a plane light wave propagating in a
homogeneous medium is known at a given instant of time. Mention
with a suitable diagram. The steps to be followed to know the
position of the wave front after time t using Huygens construction.
15. A monochromatic parallels beam of light is incident on a single slit.
Graphically show the intensity distribution among the principal
maximum and secondary maximum in the diffracted beam.
16. In a plane diffraction grating the width of each slit is equal to the
width of the opaque space between two adjacent slits. Find the
missing orders of spectra.
17. Show that the radii of the Fresnel half period zones are proportional
to the square root of natural number.
18. Give on experimental arrangement for production of elliptically
polarized light from unpolarized light.
19. Give the construction and use of a half wave plate. Com of be used
for light of all wavelengths?
20. Describe the formation of diffraction pattern due to plane
transmission grating. Explain the meaning of missing spectra in the
diffraction pattern.
21. What is optical rotation? Give the construction and working of a
device used to measure the optical relativity of optically active
solution.
22. Write down the procedure to detect different types of light.
23. What is law of males? Give the expression for emergent light from
the analyzer.
24. What is scattering? How can plane polarized light be obtained by
scattering?
25. Distinguish between Fresnel’s diffraction and Fraunhofer’s
diffraction in option.
26. What are the laws of optical rotation as stated by Biot from
experimental observation?
27. Describe the formation of diffraction pattern due to plane
transmission grating. Explain the meaning of missing spectra in the
diffraction patter.
28. How is a zone plate? Which also acts as a light converging optical
device different from a converging lens?
29. What is optical rotation? Give the construction and working of a
device used to measure the optical relativity of optically active
solution.
30. Differentiate between ordinary and extra Ordinary rays of light.
31. What is a half wave plate? Derive an expression for its minimum
thickness for a given wave length in terms of its refractive indices for
O-ray and E-ray.
32. Describe the formation of diffraction pattern due to plane diffraction
grating. Explain the meaning of missing spectra in the diffraction
pattern.
33. What is half wave plate? Derive an expression for its minimum
thickness for a given wavelength in terms of its refractive indices for
O-ray & E-ray.
34. What is optical rotation? Explain how a sacharimeter is used for the
determination of specific rotation of sugar solution.
35. Light from two monochromatic sources of wavelengths 5000 Å &
5200 Å is incident on a grating having 15000 lines /inch. The
spectrum is focused by a lens of focal length 2 m on a curved screen
of radius of curvature 2 m. Find the linear distance between the
maxima of two sources for first order & second order spectrum.
3RD QUESTION BANK FOR PHYSICS-I(UNITS-5,6,7&8)
(For Sec-B1, B2&B3, Batch-2008.
(All the questions are from BPUT sets of questions2003 to 2008)
LONG QUESTIONS
1. Write down Maxwell’s electromagnetic equations in differential form
in a medium. In the presence of charges and currents. Identify and
state the laws of electromagnetism with which these equations are a
associated.
2. Stating from Maxwell’s e.m equations in free space obtain the wave
equation in terms of scalar and vector potentials. Mention the gauge
conditions used.
3. What is photoelectric effect? Write Einstein’s photoelectric
equations and explain the terms used.
4. Write the integral form and differential forms of Gauss’s law in
electrostatics in vacuum.
5. Starting from Maxwell’s e.m equations in free space. In absence of
charges and currents. Obtain the wave equation for electric field.
6. State Poynting theorem. Explain how Poynting vector explains the
energy flow?
7. Setup the time-independent Schrödinger equation for a onedimensional harmonic oscillator.
8. State and explain Heisenberg’s uncertainty principle Use it to show
that the minimum energy of the one-dimensional harmonic oscillator
can not be zero.
9. Write Maxwell’s e.m equations in free space in the presence of
charges and currents Name each symbols used in the equations.
10. Obtain the wave equation for electric field in vacuum from
appropriate Maxwell equations.
11. Mention the characteristics of the wave function in quantum
mechanics.
12. Using Gauss divergence theorem. Prove that the volume of a sphere
of radius r is (4/3)πr3 .
13. Starting from faraday’s law of E.M. induction. Establish the relation
→→
→
ΔxE=- (∂/∂t) B
14. Obtain E.M. wave equation from. Maxwell’s equations in a charge
free and current free region.
15. Write Planck’s formula for spectral distribution of black body
radiation. Hence explain how Wien’s law and Raleigh- Jean law
follow from it.
16. Set up the Schrödinger wave equation for a particle of mass ‘m’
Crossing a potential step V(x) = 0 for x<0, V(x) = Vo for x>0 from left.
Obtain the solution & indicate the reflected and transmitted part in it.
17. State Ampere’s circuital law and obtain its differential form.
18. Draw the graph between stopping potential and frequency of
incident radiation in an experiment demonstration photoelectric
effect. Explain how the value of Planck’s constant and the
photoelectrical work function of the material can be determined from
the graph.
19. Write Gauss law of electrostatics in a dielectric medium-obtain its
differential form.
20. Starting from Maxwell’s E.M. equation obtain the equation for E in an
ionized medium. Identify the dissipative term in the equation.
21. A plane E.M. wave propagates in vacuum. The maximum value of
electric field is 500 V/m. find out the average value of Poynting vector
for the wave.
22. Evaluate the divergence of A=i xy +j y2 +k2xz at the point (2.1.0) &
also evaluate the curl at the same point.
23. Obtain the electromagnetic wave equation for E and H using
appropriate Maxwell’s equations.
24. How is Ampere’s circuital law modified due to the presence of
displacement current? Obtain the corresponding Maxwell’s equation.
25. Prove that the momentum of a particle in one dimensional potential
well of infinity height is quantized.
→^
^
Evaluate the surface integral for the vector function F=x(4xz-y)–yy2+
^
z yz over the surface ‘S’, where ‘S’ is the surface of the unit cube
bounded by x = 0, x= 1, y = 0, y =1, z= 0, z = 1 planes.
26. Show that average value of Poynting vector for a plane e.m wave is
(½)[√ (μ/ε)]X (H0)2
27. Write down Maxwell’s e.m equations in vacuum in the absence of
any charge or current.
28. State and explain Heisenberg’s uncertainty principle.
29. Prove that e.m waves are transverse in nature.
30. A scalar function is given by f(x, y, z) = 2xy2 + xyz3. Evaluate the
gradient of the function at the point (1,1,1)
31. State Gauss’s law in electrostatics. Obtain its differential form in
vacuum.
32. Distinguish between displacement current and conduction current.
33. A particle can exist in the states Ψ1, Ψ2 &Ψ3 with probabilities 0.5, 0.2
and 0.3 respectively. Find out the expectation value of energy for the
particle.
34. What do you mean by normalization of a wave function? The wave
function for certain particle is given by Ψ=cos2x for π/2 < x < π/2.
Normalize the wave function in the given range.
35. Derive the e.m wave equation in terms of electric vector when the
wave is passing through vacuum.
36. A particle having energy ‘E’ more than the height of a potential
barrier V0 is incident on it at x = 0 perpendicularly .
A exp i (k0x- Et/Ћ) & A [(k-ko)/ (k+k0)] exp [-i {kox-(Et/Ћ)}] are the wave
functions of the particle in the region x<o, where as
Aexp i (kx-Et/Ћ) is the wave function of the particle in the region x>0.
Here k0 =√ (2mE/Ћ) & k =√ {2m (E-V0)/Ћ}.
Calculate the reflection probability at x = 0.Symbols have their usual
meanings.
37. Derive an expression for the electric field intensity at a near by point
of a fine straight wire charged positively by using Gauss law of
electromagnetism.
38. A stream of electron strike on a potential energy step of height
0.04eV.Calculate the fraction of electron reflected of energy of the
incident electron is 0.05eV.
39. Derive an expression for the magnetic induction at an internal point
of a long cylindrical current carrying straight conductor by using
Ampere’s circuital law of electromagnetism.
40. What is plasma frequency? What role does it play in propagation of
e.m waves in ionized medium?
41. 1.2 million electrons with energy 1 eV are incident on a potential
barrier of 8 eV high & 0.50 nm width. Calculate how many electrons
will tunnel through the barrier?
42. A beam of electrons with certain energy is incident on a quantum
mechanical potential step of infinity height. Prove that no electrons
can penetrate this barrier.
43. E.M. waves are transverse waves; that means electric vector,
magnetic vector & propagation vector are perpendicular to each
other. Prove this statement mathematically.
Short Questions
1. Write the integral form of the Ampere’s circuital law.
2. Express the electric field in terms of vector potential and scalar
potential.
3. Transition between which energy levels of hydrogen atoms gives
rise to the spectral line of the longest wave length in the Balmer
series?
4. The wave function Ψ of a system is a linear combination of Eigen
functions Φ1, Φ2, Φ3, Φ4, Φ5.
Ψ=(Φ1/√3)+(Φ2/√3)+(Φ3/√6)+(Φ4/√24)+(Φ5/√8). What is the probability of
the system being in the state given by Φ3 ?
5. Find out the SI unit of wave function of a one dimensional harmonic
oscillator.
→
^
^
^
6. Evaluate curl A, where A=I xy+ j yz +k xz.
7. Write the time independent Schrödinger equation for a free particle
of mass ‘m’ moving along y-axis. Obtain the solution.
8. Radiation of wavelength 2400 A0 is incident on a metal surface
whose photoelectric work function is 2.3eV. Calculate the maximum
kinetic energy of the emitted photoelectrons and the stopping
potential.
9. Write the Maxwell’s e.m equations in differential form, which
follows from Faraday’s law of electromagnetic induction.
10. Write the wave equation for electric field E in an ionized medium.
11. A particle of mass ‘m’ moves along the y-axis under a potential
v(y). Write the time dependent Schrödinger equation for the
particle,.
12. For which angle of scattering is the Compton shift maximum?
Explain with appropriate formula.
13. A particle is in one dimensional infinitely deep potential well of
width ‘L’. Write the dependence of ground state energy on the
width of the well.
14. Distinguish between conduction current and displacement current.
Give examples.
→→
→ ^
^
^
15. Evaluate Δ.F , where F = i 2xy +j x2y2+k xyz.
16. A laser beam from 100Watt source is focused on area of 10-5m2.
Evaluate the magnitude of Poynting vector on that area.
17. Calculate the de-Broglie wavelength of a particle of mass 10gm
moving with a speed of 310m/sec.
18. Write the time dependent Schrödinger equation for a free particle
of mass ‘m’ moving along the z-axis.
19. X-rays of wavelength 1.2A0 under Compton scattering due to
electrons. What is the maximum possible value of Compton shift if
the Compton wavelength of electron is 0.02426 A0?
20. Define Poynting vector. Mention its dimension and SI unit.
21. A vector field is given by F = i 2x + j 5y. Evaluate the divergence of
the vector.
22. Write the second form of the Green’s theorem.
23. Write down the relation between B, H and M. Where B is the
magnetic induction, H is the magnetic field and M is the intensity of
magnetization.
24. Mention the transition levels of electrons corresponding to the
longest wavelength in Paschen series of H-atom.
25. Use uncertainty relation to show that electrons can not stay in the
nucleus.
26. Write the Maxwell’s e.m equation which follows from the non
existence of isolated magnetic pole.
27. A plane e.m wave travels vertically upward. If the magnetic field of
the e.m wave is eastward, what is the direction of the associated
electric field?
28. In an experiment demonstrating photoelectric effect, the maximum
KE of the emitted photo electrons 1.6 eV. The source of
monochromatic light is moved away from the photocell, so that the
intensity of light incident on the photocell decreased by 10%. How
is the maximum KE of the photo electrons affected?
29. Transition between which energy levels of hydrogen atom
produces the most intense spectral line of Balmer series?
30. A particle in one dimensional infinitely deep potential well. If its
ground state energy is 0.8 eV, what is the energy of the second
excited state?
31. Write the boundary conditions satisfied by the quantum mechanical
wave function at the boundary between two regions.
32. Evaluate the divergence of the vector field F =i 2xy + j y2 + k 3xyz at
(110).
33. Evaluate the de-Broglie wavelength of a particle of mass 6.62 x 10-30
kg moving with speed 10cm/sec.
34. The electric field between two parallel metal poles of area 1cm2
charges at the rate of 1.2 x 108 V/m.s. Calculate the displacement
current.
35. Write the relation between the wave function of a particle in a given
state and the possibility per unit volume of finding the particle in
the given state.
36. The allowed values of energy of a quantum mechanical system are
E1, E2, E3 and E4 with probabilities 0.2, 0.1, 0.4 and 0.3 respectively.
Find the expectation value of energy for the system.
37. The ground state energy of a particle on fixed to an infinitely deep
one dimensional potential well is 0.002 eV. Find the energy of the
second excited state.
38. Evaluate x r where r is the position vector.
39. Write the Maxwell’s e.m equation in free space, which follows from
Gauss law in electrostatics.
40. Express electric field in terms of scalar potential and vector
potential.
41. A particle moves with speed equal to 1/1000th of the speed of light
in vacuum. What is the ratio of de-Broglie wavelength of the
particle to its Compton wavelength?
42. A particle in one-dimensional infinitely deep potential well. At
which position is the probability of finding the particle maximum,
when it is in the ground state.
43. State Gauss divergence theorem for a vector field.
44. One of the Maxwell’s e.m equations involves the curl of the electric
field .write the equation and mention the law of electromagnetism
which is represented by the equation.
45. The magnetic vector potential in a given region is a constant
vector having magnitude 4π x 105 units and points along the
positive X-axis. What is the magnitude of the magnetic induction in
the region?
46. The de-Broglie wavelength of the particle moving with velocity
200m/s is 14.14 A0. What will be the de-Broglie wavelength if its
kinetic energy is doubled?
47. A plane electromagnetic wave propagates along vertically
downward direction .At a given instant, the direction of E at a point
is towards east, what is the direction of B?
48. The ground state energy of a particle confined to an infinitely deep
one dimensional potential well is 0.002eV. Find the energy of the
second excited state.
49. An X-ray beam of wavelength 3A0 is Compton scattered by
electrons. Evaluate the Compton shift of a beam scattered at an
angle 600.
50. Write the time dependent Schrödinger equation for a particle of
mass ‘m’ moving along the y-axis under a potential V =ay2.
51. In free space electric field intensity is given by E = y 20cos (wt –
50x) Volt/meter. Calculate displacement current density.
52. What is the physical significance of curl of a vector function?
53. Express the magnetic field in terms of magnetic vector potential
and magnetic scalar potential.
54. A medium is characterized by relative permittivity εr = 45 and
relative permeability μr = 5. calculate the speed of e.m waves in the
medium and refractive index of the medium.
55. One electron and one proton are moving with same kinetic energy.
Find the ratio of their de-Broglie wavelengths. Their masses are
9.11 x 10-31 kg and 1.67 x 10-27 kg respectively.
56. 12 million electrons with energy 3.0 eV are incident on a potential
barrier of 9.0 eV high and 0.50 nm width. Calculate how many
electrons will tunnel through the barrier?
57. State Stoke’s theorem in vector calculus.
58. Isolated magnetic poles do not exist in nature. Write the Maxwell’s
e.m equation which depicts this.
59. A plane e.m wave propagates horizontally from east to west. If the
magnetic field associated with the wave at a point in its paths is
towards north, what is the direction of associated electric field at
that point?
60. The maximum K.E of photo electrons ejected from a metal, which is
illuminated by light from a monochromatic source, is 2.6 eV. What
would be the maximum K.E of the intensity of incident light is
doubled?
61. A particle in a one dimensional infinite deep potential well. What is
the dimension of the wave function of the particle?
62. State Gauss’s law in electrostatics. Obtain its differential form in
vacuum.
63. Write down the time dependent Schrödinger equation for a particle
of mass ‘m’ moving along the y-axis under a potential V(y) = 2ay.
64. The de-Broglie wavelength of a particle is 1000A0. What is its linear
momentum?
65. The radius of the orbit of the electron in the ground state of
Hydrogen atom is 0.5A0. What is the radius of the orbit in the 1st
excited state?
66. A particle can exist in the states Ψ1 , Ψ2,Ψ3 with probabilities 0.5,
0.2 and 0.3 respectively. The energy eigen values in the three states
are E1 = 2eV, E2 = 4eV & E3 = 8eV respectively. Find out the
expectation value of energy of the particle.
67. State Stoke’s theorem in vector calculus.
68. Isolated magnetic poles don’t exist in nature.Write the Maxwell’s
e.m. equations which depicts this.
69. A plane electromagnetic (e.m), wave propagates horizontally from
east to west. If the magnetic field associated with the wave at a
point in its path is towards north, what is the direction of
associated electric field at that point?
70. A particle is in a one dimensional, infinite deep potential well. What
is the dimension of the wave function of the particle?
71. The maximum K.E of the photo electrons ejected from material,
which is illuminated by light from a monochromatic source, is
2.6eV. What would be the maximum K.E of the intensity of incident
light is doubled?
72. A particle is in a one dimensional, infinite deep potential well. What
is the dimension of the wave function of the particle?
73. Write the time dependent Schrödinger equation for a particle of
mass ‘m’ moving along the y-axis under a potential V(y) = 2 ay.
74. The de-Broglie wavelength of a particle is 1000A0. What is the linear
momentum?
75. The radius of the orbit of the electron in the ground state of
hydrogen atom is 0.5A0. What is the radius of the orbit in the first
excited state?
76. Write the Maxwell’s equation which supports the idea of absence of
magnetic monopoles.
77. Give the non mathematical statement of Poynting’s theorem.
78. Give a relation between classical physics & quantum physics.
79. The width of an infinity deep potential well is halved. What will
happen to the energy of particle dropped inside it?
80. State the Maxwell’s equation an electromagnetism connecting
magnetic field vector and electric displacement vector.
81. Derive the relation between displacement current and the
magnitude of electric displacement.
82. State Huygens’s principle. According him what type of wave is
light?
83. Calculate the speed of e.m wave in vacuum. Data given are E0 =
8.8547 x 10-12 Coulomb2/Newton.meter2 and μ0 = 4π x 10-7
Weber/Amp.meter.
84. What are the laws of photoelectric effects?
85. What do you mean by plasma angular frequency of a medium?
86. Write down the all Maxwell’s electromagnetic wave equations.
87.Why quantization of energy is not observed in every day life ?
88. Write the time independent Schrodinger’s equation for a free
particle of mass ‘m’ moving in xy-plane.
89.The probability that a system can be in the states represented by
eigenfunctions Ψ1,Ψ2,Ψ3 are 1/2, 1/3 & ¼ respectively. Write the
wave functions for the system. If the energy eigen values for the
above states are 2 eV,3eV,4eV respectively, find the energy
expectation value.
90.Derive the e,m wave equation in terms of magnetic vector potential
& scalar potential when the wave is propagating in vacuum.