1. No category

KONGUNADU COLLEGE OF ENGINEERING AND TECHNOLOGY, TRICHY
DEPARTMENT OF PHYSICS
HS 1102 - ENGINEERING PHYSICS – I
QUESTION BANK
Unit – I – ULTRASONICS
TWO MARKS QUESTIONS
1.
What is Ultrasonics? Name the methods to produce Ultrasonics.
2.
Are the Ultrasonics waves electromagnetic waves? Give proper reason.
3.
Give the properties of Ultrasonics.
4.
What is magnetostriction effect?
5.
Define the terms “piezo electric effect” and “inverse piezo electric effect”
6.
What is cavitation? Mention its applications.
7.
What is an acoustical grating?
8.
Name the methods to detect Ultrasonics.
9.
List the industrial applications of Ultrasonics.
10. What is SONAR? Give its applications.
11. What is NDT? List the name of NDT techniques.
12. Compare destructive and non-destructive testing.
13. What is the principle of NDT by Ultrasonic? Name different scanning methods used
in Ultrasonic NDT.
14. What is the principle of Ultrasonics flaw detector?
15. What are the medical applications of Ultrasonics?
16. What is Sonogram?
17. What are the advantages of Ultrasonics in medical field over other technique?
SIXTEEN MARKS QUESTIONS
1. What is magnetostriction effect? Describe the production of ultrasonic waves by
magnetostriction oscillator method. Give the merits and demerits of this method.
2. What is inverse Piezo-electric effect? Describe the production of ultrasonic waves by
piezo electric oscillator method. Give the merits and demerits of this method.
1
3. Explain the various techniques adopted in detecting the ultrasonic waves.
4. Explain the determination of velocity of ultrasonic sound using an acoustical grating.
5. What is meant by SONAR? Explain in detail how SONAR is employed to locate
the objects? What are the applications of SONAR?
6. Describe the principle, construction and working of ultrasonic flaw detector. Explain
the three different scanning methods.
7. What is sonogram? Explain how it is used in medical filed.
PROBLEMS
1. A Quartz crystal of thickness 0.001 m vibrates in its fundamental frequency. Calculate
its frequency. (Given that E= 7.9X1010 and ρ = 2650Kg/m3 for quartz)
2. An ultrasonic interferometer used to measure the velocity in sea water. If the distance
between two constructive anti nodes is 0.55 mm. Compute the velocity of the waves
in the sea water. The frequency of the crystal is 1.5 MHz.
3. Longitudinal standing waves are setup in a quartz plate with anti nodes at opposite
faces. The fundamental frequency of vibration is given by the relation F=2.87x10 3/t.
Where F is in Hz and t is in meter. Compute (a) Young’s modulus of quartz plate
(b) Thickness of the plate required for the frequency of 1300 KHz. Density of quartz
is 2660Kg/m3
Unit – II – LASERS
TWO MARKS QUESTIONS
1. Distinguish ordinary light and LASER light.
2. What is meant by LASER? Give its characteristics.
3. What is the principle of LASER?
4. What are the conditions to achieve the LASER action?
5. Define the terms “normal population” and “population inversion”.
6. Define the terms “Spontaneous emission” and “Stimulated emission”.
7. Define pumping. Name the types of pumping.
8. What are the types of LASER with example?
2
9. What are the uses of Nitrogen and Helium in CO2 LASER?
10. Compare homojunction and heterojunction LASER.
11. What is holography? Mention its uses.
12. Distinguish photography and holography
13. State applications of LASER in Communications.
14. Mention the applications of LASER in medical and engineering.
SIXTEEN MARKS QUESTIONS
1. Explain the principle spontaneous and stimulated emission and derive the equation for
Einstein’s coefficients.
2. Describe the principle, construction and working of He -Ne Laser. Mention its uses.
3. Describe the principle, construction and the working of CO2 Laser and mention its
uses.
4. Describe the principle, construction and working of Nd: YAG Laser. Mention its uses.
5. Explain the principle, construction and working of Semi-Conducting homo-junction
and hetero – junction lasers.
6. Discuss the applications of Laser in a) Industry b) Medical.
7. Describe the principle, Construction and Reconstruction of Holography. Write a note
on applications of holography.
PROBLEMS
1. Calculate the wavelength of emission from GaAs semiconductor laser, whose band
gap energy is 1.44eV.
2. Helium neon laser emits light at a wavelength of 632.8nm and has output power of
laser is 5mWatt. How many photons are emitted per second by this laser when
operating?
3. For InP laser diode, the wavelength of light emission is 1.55µm. What is its band gap
in eV?
3
Unit – III – FIBER OPTICS
TWO MARKS QUESTIONS
1. What is optical fiber? Name different types of optical fiber.
2. What is the structure of fiber? And what are the features of fiber optics?
3. What is total internal reflection? Write the condition to achieve total internal
reflection.
4. Define critical angle.
5. Define acceptance angle and numerical aperture.
6. Distinguish single mode and multi mode fiber.
7. Distinguish step index and graded index fiber.
8. Name the types of losses in fiber optics.
9. What is meant by splicing?
10. What is attenuation?
11. What is sensor? Name the types of sensors.
12. Name the types of source and detectors used in fiber optic communication system.
SIXTEEN MARKS QUESTIONS
1. Explain the propagation of light through the optical fiber. Define the terms
“Numerical Aperture” and “Acceptance Angle”.
Deduce the expressions for
acceptance angle and numerical aperture.
2. Explain in detail, the various types of optical fiber. Describe double crucible
technique for manufacturing optical fiber.
3. Explain different types of losses in optical fiber.
4. Describe construction and working of fiber optic communication system with neat
sketch.
5. Explain in detail any one of the light source and detector used in optical fiber
communication system.
6. What is sensor? Name the different types of fiber optic sensors? Explain the working
of displacement and temperature sensors.
7. Describe the construction and working of medical endoscope.
4
PROBLEMS
1. Calculate the refractive indices of core and cladding materials of an optical fibre if its
numerical aperture is 0.22 and relative refractive index difference is 0.012.
2. Calculate the Numerical Aperture and Acceptance angle of an optical fibre from the
following data. Refractive index of core is 1.54 and cladding is 1.50
3. A silica optical fibre has a core refractive index of 1.50 and cladding refractive index
of 1.47. Calculate the critical angle of the core-cladding interface.
Unit – IV – QUANTUM PHYSICS
TWO MARKS QUESTIONS
1. Define the terms “black body” and “black body radiation”.
2. What are the postulates of Planck’s quantum theory?
3. State the hypothesis of Planck theory.
4. What is meant by photon? Give any two properties.
5. Define Stefen- Boltzmen law.
6. Define wien’s displacement law. Give its limitations.
7. Define Rayleigh-Jeans law. Give its limits.
8. Define the terms “Compton Effect” and “Compton shift”.
9. What is Compton wavelength? And give its value.
10. What is De – Broglie wave? Give its properties.
11. What is meant by matter waves?
12. What is wave function? Give the significance of wave function.
13. Define Eigen value and Eigen function.
14. Define “degeneracy state” and “non- degeneracy state”.
15. What is the principle of electron microscope?
16. What is Schrödinger’s wave equation? Write two equations.
5
SIXTEEN MARKS QUESTIONS
1. State Planck’s Hypothesis. Derive Planck’s law for black body radiation and hence
deduce Wien’s Displacement law and Rayleigh – Jean’s law.
2. What is Compton Effect? Derive the equation for Compton shift. Explain the
experimental verification of Compton Effect.
3. Explain the principle, construction and working of Electron Microscope with neat
sketch.
4. What is Schrödinger’s wave equation? Derive Time-dependent and Time-independent
wave equations.
5. Derive the expression for energy levels of a particle enclosed in one-dimensional
potential box of width “a” and infinite height.
PROBLEMS
1. The wavelength of X-ray photon is doubled when it is scattered through an angle of
90˚by a target material. Find the incident wavelength.
2. Find the change in wavelength of an X-ray photon when it is scattered through an
angle of 135˚ by a free electron (h=6.63 x10 -34 Js, m0 = 9.1 x 10-31 Kg, c= 3x 108m/s)
3. The de Broglie wavelength of an electron is 1.226A˚. What is the value of
accelerating potential?
4. Calculate the de Broglie wavelength of an electron which has been accelerated from
rest on application of potential of 400Volts.
Unit – V – CRYSTAL PHYSICS
TWO MARKS QUESTIONS
1. Distinguish crystalline solids and amorphous solids.
2. Define the term “lattice plane”.
3. Define the terms “space lattice” and “Bravais lattice”.
4. Define the term “unit cell”.
6
5. What are “primitive cell” and “non primitive cell”?
6. Define the term “coordination number”,
7. Define the term “number of atoms per unit cell”.
8. Define “atomic radius”.
9. Define “atomic packing factor”.
10. What are the co-ordination numbers for SC, BCC and FCC?
11. What are Miller indices? Give the procedure to find Miller indices.
12. Define Miller Indices and draw the crystal planes for (1 1 0), (0 0 1).
SIXTEEN MARKS QUESTIONS
1. Define the terms “Coordination number”, “Number of atoms per unit cell”, “atomic
radius” and “Atomic packing Factor”. Calculate the above for SC, BCC and FCC
structures.
2. Define “Atomic packing Factor”. Deduce the c/a ratio for HCP structure.
3. Deduce the relation between inter planar distance‘d’ and lattice constant ‘a’
4. What are Miller indices? Write the procedure to find Miller indices.
5. Explain diamond, NaCl, ZnS and Graphite structures with necessary diagrams.
PROBLEMS
1. Calculate inter planar spacing (1 0 1) in a simple cubic crystal whose lattice constant
is 0.42nm.
2. Iron has BCC structure with atomic radius 0.123A˚. Find the lattice constant and also
the volume of the unit cell.
3. The lattice constant of a metal with cubic lattice is 2.88A˚. The density of metal is
7200Kg/m3. Calculate the number of unit cell present in 1 Kg of the metal.
4. Calculate the lattice constant and distance between two adjacent atom form Potassium
bromide crystals (FCC lattice) having the density and molecular weight of
2700Kg/m2 and 119 gram respectively.
5. Magnesium has HCP structure. The radius of atom is 0.1605 nm. Calculate the
volume of the unit cell of Magnesium.
7