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R18 B.Tech. I Year Syllabus, , JNTU HYDERABAD, , JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD, B.Tech. I Year COURSE STRUCTURE & SYLLABUS (R18 Regulations), Common for ECE, EIE (Old Branches) and, CSE (AI & ML), CSE (IoT), & ECM – These three Branches are from AY 2020-21., AI and ML, AI & DS – These Two Branches are from AY 2021-22., , I YEAR I SEMESTER, Course, S. No., Code, 1, MA101BS, 2, AP102BS, 3, CS103ES, 4, ME104ES, 5, AP105BS, 6, CS106ES, 7, *MC109ES, , I YEAR II SEMESTER, Course, S. No., Code, 1, MA201BS, 2, CH202BS, 3, EE203ES, 4, ME205ES, 5, EN205HS, 6, CH206BS, 7, 8, , EN207HS, EE208ES, , Course Title, , L, , T, , P, , Credits, , 3, 3, 3, 1, 0, 0, 3, , 1, 1, 1, 0, 0, 0, 0, , 0, 0, 0, 4, 3, 3, 0, , 4, 4, 4, 3, 1.5, 1.5, 0, , 13, , 3, , 10, , 18, , L, , T, , P, , Credits, , Mathematics – II, Chemistry, Basic Electrical Engineering, Engineering Workshop, English, Engineering Chemistry Lab, , 3, 3, 3, 1, 2, 0, , 1, 1, 0, 0, 0, 0, , 0, 0, 0, 3, 0, 3, , 4, 4, 3, 2.5, 2, 1.5, , English Language and Communication Skills Lab, Basic Electrical Engineering Lab, , 0, 0, , 0, 0, , 2, 2, , 1, 1, , Total Credits, , 12, , 2, , 10, , 19, , Mathematics – I, Applied Physics, Programming for Problem Solving, Engineering Graphics, Applied Physics Lab, Programming for Problem Solving Lab, Environmental Science, Induction Programme, Total Credits, , Course Title, , *MC – Mandatory Course – Satisfied/Unsatisfied, , 1

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R18 B.Tech. I Year Syllabus, , JNTU HYDERABAD, AP102BS/AP202BS: APPLIED PHYSICS, , B.Tech. I Year I Sem., , L, 3, , T P C, 1 0 4, , Course Objectives:, Students will demonstrate skills in scientific inquiry, problem solving and laboratory techniques., Students will be able to demonstrate competency and understanding of the concepts found in, Quantum Mechanics, Fiber optics and lasers, Semiconductor physics and Electromagnetic, theory and a broad base of knowledge in physics., The graduates will be able to solve non-traditional problems that potentially draw on knowledge, in multiple areas of physics., To study applications in engineering like memory devices, transformer core and electromagnetic, machinery., Course Outcomes: Upon graduation:, The student would be able to learn the fundamental concepts on Quantum behaviour of matter, in its micro state., The knowledge of fundamentals of Semiconductor physics, Optoelectronics, Lasers and fibre, optics enable the students to apply to various systems like communications, solar cell, photo cells, and so on., Design, characterization and study of properties of material help the students to prepare new, materials for various engineering applications., The course also helps the students to be exposed to the phenomena of electromagnetism and, also to have exposure on magnetic materials and dielectric materials., UNIT - I: Quantum Mechanics, Introduction to quantum physics, Black body radiation, Planck’s law, Photoelectric effect, Compton, effect, de-Broglie’s hypothesis, Wave-particle duality, Davisson and Germer experiment, Heisenberg’s, Uncertainty principle, Born’s interpretation of the wave function, Schrodinger’s time independent wave, equation, Particle in one dimensional box., UNIT - II: Semiconductor Physics, Intrinsic and Extrinsic semiconductors, Dependence of Fermi level on carrier-concentration and, temperature, Carrier generation and recombination, Carrier transport: diffusion and drift, Hall effect, pn junction diode, Zener diode and their V-I Characteristics, Bipolar Junction Transistor (BJT):, Construction, Principle of operation., UNIT - III: Optoelectronics, Radiative and non-radiative recombination mechanisms in semiconductors, LED and semiconductor, lasers: Device structure, Materials, Characteristics and figures of merit, Semiconductor photodetectors:, Solar cell, PIN and Avalanche and their structure, Materials, working principle and Characteristics., UNIT - IV: Lasers and Fibre Optics, Lasers: Introduction to interaction of radiation with matter, Coherence, Principle and working of Laser,, Population inversion, Pumping, Types of Lasers: Ruby laser, Carbon dioxide (CO2) laser, He-Ne laser,, Applications of laser. Fibre Optics: Introduction, Optical fibre as a dielectric wave guide, Total internal, reflection, Acceptance angle, Acceptance cone and Numerical aperture, Step and Graded index fibres,, Losses associated with optical fibres, Applications of optical fibres., UNIT - V: Electromagnetism and Magnetic Properties of Materials, Laws of electrostatics, Electric current and the continuity equation, Ampere’s and Faraday’s laws,, Maxwell’s equations, Polarisation, Permittivity and Dielectric constant, Internal fields in a solid,, Clausius-Mossotti equation, Ferroelectrics and Piezoelectrics. Magnetisation, permeability and, 4

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mid-1, applied physics, question bank, , Note:, , ****, , very important question, , ***, , Important question, , **, , Rarely asked question

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VIGNAN S INSTITUTE OF TECHNOLOG & SCIENCE, APPLIED PHYSICS (2019-20) (I/II-SEM), UNIT I, QUANTUM MECHANICS, S.No., ***1., , Question, a) Define Black body radiation., b) Explain the concept of Planck s la ., c) Derive the expression for average energy of, q an m oscilla ors and Plank s Form la .E plain, its two special cases., *** 2. a) What is Compton Effect?, b) Calculate the value of Compton wave length., c) Derive the expression for Compton shift., ** 3 a) What is Photo electric effect?, b) Explain quantum theory of photo electric effect., , c) Write the fundamental laws of photo electric, effec and Deri e he e pression for Eins ein s, photo electric equation, **4. a) Wha is Heisenberg s Uncer aini principle?, b) Explain the Physical Significance of Uncertainity, principle, c) Write any two applications of Uncertainity, principle., *** 5. a) Explain dual nature of light., b) Define the matter waves and Explain the, properties of matter waves., c) Explain construction and working of Davision, and Germer experiment to prove that the moving, matter particle is associated with a wave., *** 6. a) Write the relation between velocities of matter, wave and lightwave., b) Sho ha he a eleng h ( ) of an elec ron, having mass (m) and kinetic energy (E) is given by, , Marks, 2M, 3M, 10M, , CO, 1, 1, 1, , PO, 1-8,10,12, 1-8,10,12, 1-8,10,12, , BTL, I, II, VI, , 2M, 3M, 10M, 2M, 3M, 10M, , 1, 1, 1, 1, 1, 1, , 1-8,10,12, 1-8,10,12, 1-8,10,12, 1-8,10,12, 1-8,10,12, 1-8,10,12, , I, III, VI, I, II, III&VI, , 2M, 3M, , 1, 1, , 1-8,10,12, 1-8,10,12, , I, II, , 10M, , 1, , 1-8,10,12, , IV, , 2M, 3M, , 1, 1, , 1-8,10,12, 1-8,10,12, , II, 1, , 10M, , 1, , 1-8,10,12, , IV, , 2M, , 1, , 1-8,10,12, , III, , 3M, , 1, , 1-8,10,12, , III, , 10M, , 1, , 1-8,10,12, , h, 2mE, , **7., , c) Deri e Schrodinger s ime independen a e, equation and what is the physical significance of, wave function, a) Wha is Born s in erpre a ion., b) Derive the expression for the wavelength of the, matter waves., c) Obtain the expression for Eigen value and Eigen, function of a particle in one dimensional potential, box., , VI, 2M, 3M, , 1, 1, , 1-8,10,12, 1-8,10,12, , II, , 10M, , 1, , 1-8,10,12, , VI

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UNIT 1-PROBLEMS, (Choose only one problem from this list), -REge--oBqB→grAdB, S.No., 1, , 2, 3, 4, 5, , Question, When light of wavelength 3000A0 is incident on, Potassium, the emitted electrons have maximum, kinetic energy of 1.91eV. What is the work, function for Potassium?, X-rays of wavelength 1A0 are scattered from a, target. Find the wavelength of the X-rays scattered, through 45 degrees., Calculate the de-Broglie wavelength associated, with a proton moving with a velocity of 1/10th of, velocity of light. (Mass of proton = 1.67 X 1027Kg)., An electron is bound in one-dimensional infinite, well of width 10-10m. Find the energy values in the, ground state and first two excited states., Calculate the wavelength associated with an, electron having energy 2000 eV., , Marks CO, 3M, 1, , PO, 1-8,10,12, , BTL, V, , 3M, , 1, , 1-8,10,12, , V, , 3M, , 1, , 1-8,10,12, , V, , 3M, , 1, , 1-8,10,12, , V, , 3M, , 1, , 1-8,10,12, , V

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UNIT II, SEMICONDUCTOR PHYSICS, S.No., , Question, , ****1. a) What are donor and acceptors? Give two, examples of each., b) Explain intrinsic and extrinsic semiconductors., c) Derive expression for carrier concentration of, N-type semiconductor and how fermi level varies, with respect to doping concentration and, temperature., *2., a) Define fermi level., b) Write the difference between N-type and PType semiconductors., c) Derive expression for carrier concentration of, P-type semiconductor and how fermi level varies, with respect to doping concentration and, temperature., a) What is Hall effect?, ***3., b) Write the applications of Hall effect., , ***4., , ***5., , **6., ****, *, , Marks, , CO, , PO, , BTL, , 2M, , 2, , 1-8,10,12, , I, , 3M, 10M, , 2, 2, , 1-8,10,12, 1-8,10,12, , II, VI, , 2M, 3M, , 2, 2, , 1-8,10,12, 1-8,10,12, , I, IV, , 10M, , 2, , 1-8,10,12, , VI, , 2M, 3M, 10M, , 2, 2, 2, , 1-8,10,12, 1-8,10,12, 1-8,10,12, , I, II, II, &VI, , 1-8,10,12, 1-8,10,12, 1-8,10,12, , I, II, IV, , 1-8,10,12, 1-8,10,12, , I, II, , 1-8,10,12, , III, &IV, , 1-8,10,12, 1-8,10,12, 1-8,10,12, , I, II, III&II, , c) Derive a relation between Hall Voltage and, Hall Coefficient and Explain experiment of Hall, effect., a) Define the terms Drift and diffusion., 2M, 2, b) Explain carrier generation and recombination., 3M, 2, c) Describe V-I characteristics of Zener diode and 10M, 2, pn junction diode in both biasing conditions., a) Define Depletion region., 2M, 2, b) Expain the band energy diagram of pn junction 3M, 2, diode., c) With the suitable schematic diagram, explain, 10M, 2, construction and principle of operation of bipolar, junction transistor., a) What is the saturation current?, 2M, 2, b) Write a short note Zener diode., 3M, 2, c) Derive the expression for the number electrons, 10M, 2, and holes in pure semiconductor., ***************************************

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UNIT-III, OPTO-ELECTRONICS, , S.No., ***1., , ***2., , Question, , Marks, , a) Explain the recombination process, 2M, b) Describe direct and indirect band gap, 3M, semiconductors, 10M, c) Explain radiative and non-radiative, recombination mechanisms in semiconductors., a) What is LED and write about its device, 2M, materials., b) List out the applications of LED, 3M, c) Explain the construction and working, figure of, 10M, merit and Characteristics of LED, ************************************, , CO, , PO, , BTL, , 3, 3, , 1-8,10,12, 1-8,10,12, , II, IV, , 3, , 1-8,10,12, , IV, , 3, , 1-8,10,12, , I, II, , 3, 3, , 1-8,10,12, 1-8,10,12, , IV, IV, , UNIT II AND III PROBLEMS, (Choose only one problem from this list), S.No., 1, , Question, The Hall co-efficient of a specimen is 3.66 X 10-4, m3C-1. Its resistivity is 8.93 X 10-3 Ohm m. Calculate, mobility and electron carrier concentration., , 2, , For an intrinsic semiconductor having band gap of, 3M, 0.78eV.Find the carrier concentration at 370C, A semiconductor plate having thickness of 1.25mm is 3M, subjected to a magnetic field of 0.55 tesla, parallel to, its thickness. If one milli-ampere current flows along, the length of the plate.calculate the Hall voltage, developed. [given the Hall coefficient =3.45X10-4, m3/coulomb], Calculate the wavelength of emitted radiation from, 3M, GaAs which has a band gap of 1.44eV., , 3, , 4, , Marks CO, PO, 2M, 2, 1-8,10,12, , BTL, V, , 2, , 1-8,10,12, , V, , 2, , 1-8,10,12, , V, , 3, , 1-8,10,12, , V

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mid-1, applied physics, question bank, , Note:, , ****, , very important question, , ***, , Important question, , **, , Rarely asked question

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VIGNAN S INSTITUTE OF TECHNOLOG & SCIENCE, APPLIED PHYSICS (2019-20) (I/II-SEM), UNIT I, QUANTUM MECHANICS, S.No., ***1., , **** 2., ** 3, , ***4., *** 5., , **** 6., , ***7., , Question, a) Define Black body radiation and Explain the, concept of Planck s law., b) Derive the expression for average energy of, quantum oscillators and Plank s Formula., a) What is Compton Effect? Explain quantum theory, of Compton effect., b) Derive the expression for Compton shift., , Marks, 7M, , CO, 1, , PO, 1-8,10,12, , BTL, I, , 8M, , 1, , 1-8,10,12, , VI, , 7M, , 1, , 1-8,10,12, , I,III,IV, , 8M, 7M, , 1, 1, , 1-8,10,12, 1-8,10,12, , VI, I,II, , b) Write the fundamental laws of photo electric, effect and Derive the expression for Einstein s, photo electric equation, a) write note Heisenberg s Uncertainit principle?, b) Write any two applications of Uncertainity, principle., a) Explain dual nature of light and de-Broglie, hypothesis., b) Explain construction and working of Davision, and Germer experiment to prove that the moving, matter particle is associated with a wave., a) Derive Schrodinger s time independent wave, equation and what is the physical significance of, wave function, b) explain about Born interpretation., , 8M, , 1, , 1-8,10,12, , III&VI, , 7M, 8M, , 1, 1, , 1-8,10,12, 1-8,10,12, , I, IV, , 7M, , 1, , 1-8,10,12, , I,II, , 8M, , 1, , 1-8,10,12, , IV, , 8M, , 1, , 1-8,10,12, , III, , 7M, , 1, , 1-8,10,12, , III, , a) Derive the expression for the de-Broglie, wavelength of the matter waves and electron, b) Obtain the expression for Eigen value and Eigen, function of a particle in one dimensional potential, box., , 7M, , 1, , 1-8,10,12, , 8M, , 1, , 1-8,10,12, , a) What is Photo electric effect? Explain quantum theory, of photo electric effect., , VI

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UNIT II, SEMICONDUCTOR PHYSICS, S.No., , Question, , ****1. a) Derive expression for carrier concentration of, N-type semiconductor, b) How fermi level varies with respect to doping, concentration and temperature., **2., a) Define fermi level. And Write the difference, between N-type and P-Type semiconductors., b) Derive expression for carrier concentration of, P-type semiconductor and how fermi level varies, with respect to doping concentration and, temperature., a) What is Hall effect? Write the applications of Hall, ***3., , ***5., , CO, , PO, , BTL, , 8M, , 2, , 1-8,10,12, , I,IV, , 7M, , 2, , 1-8,10,12, , II, , 7M, , 2, , 1-8,10,12, , I,II, , 8M, , 2, , 1-8,10,12, , VI, , 7M, , 2, , 1-8,10,12, , I,II, , b) Derive a relation between Hall Voltage and, 8M, 2, Hall Coefficient and Explain experiment of Hall, effect., a) Write a short note Zener diode., 7M, 2, b) With the suitable schematic diagram, explain, 8M, 2, construction and principle of operation of bipolar, junction transistor., a) Explain the working of p-n junction in forward 7M, 2, and reverse bias and explain V-I characteristics of, p-n junction diode, b) Derive the expression for the number electrons 8M, 2, and holes in pure semiconductor., ***************************************, , 1-8,10,12, , II, &VI, , 1-8,10,12, 1-8,10,12, , II, III, &IV, , 1-8,10,12, , I.II, , 1-8,10,12, , III&II, , effect., , ***4, , Marks

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UNIT-III, OPTO-ELECTRONICS, , S.No., ***1., , ***2., , Question, , Marks, , a) Describe direct and indirect band gap, 7M, semiconductors, 8M, b) Explain radiative and non-radiative, recombination mechanisms in semiconductors., a) What is LED and write about its device materials 7M, and list out the applications of led., c) Explain the construction and working, figure of, 8M, merit and Characteristics of LED, ************************************, , CO, , PO, , BTL, , 3, , 1-8,10,12, , II, , 3, , 1-8,10,12, , IV, , 3, , 1-8,10,12, , I, II, , 3, , 1-8,10,12, , IV

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APPLIED PHYSICS BIT BANK, UNIT-1, Multiple choice type questions:, 1., , We do not observe matter waves in heavy particles because, a) The wavelength associated is very large b) The wavelength associated is very small, c) They travel with lesser velocity, , 2., , 3., , Velocity of matter waves is always, a) Less than velocity of light, , b) equal to velocity of light, , c) Greater than velocity of light, , d) none of these, , Existence of matter waves was experimentally first demonstrated by, a) Newton, , 4., , 5., , d) none of these, , b) Plank, , c) Davison and Germer, , d) de-Broglie, , In which experiment Ni is used as target material, a) G.P Thomson s experiment, , b) Compton effect, , c) Davisson & Germer Experiment, , d) None, , In Davission and Germer s experiment the first order diffraction maximum is observed, When the angle between the incident and reflected rays is, a) 45, b) 90, c) 50, d) 180, , 6. If a particle of mass m is trapped inside a potential well of length L and infinite depth its energy, is given by, a) En, , n2 h2, 8mL2, , b) En, , n 2 L2, 8mh 2, , c) En, , 8, , 2, , m2 h2, n 2 L2, , d) En, , nhL, 2 m, , 7. The de Broglie wave associated with a moving particle is, a) An infinite monochromatic wave, , b) A finite monochromatic wave, , c) A wave packet having a group velocity equal to that of the moving particle, d) None, 8. Davission and Germer experiment is related to, a) Interference, , b) polarization, , c) Electron diffraction, , d) verification of Bohr s theory, , 9. The expression of the momentum of a photon is, a) p = hλ, , b) p = h/λ, , c) p = c/λ, , d) None

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10. The wave function for a particle must be normali e because the particle s, a) Charge must be conserved, , b) Momentum must be conserved, , c) Must be somewhere, , d) None, , 11. Energy Time Uncertainty relation is ------------------------------12. The wavelength, expressed in nm, of a photon of energy equal to 1 keV is equal to:, a) λ = 0.124nm, , b) λ = 1.24nm c) λ = 12.407nm, , d) None, , 13. An electron is confined to move in a one dimensional potential well of length 5Å. Find the, quantized energy values for the lowest energy state., a) 1.5 eV, b), 0.15 eV, c), 15 eV, d), None, 14. Which of the following particles moving with the same velocity has longest waves associated, with it?, a) Proton, b), electron, c) neutron, d) a - particle, 15. The probability of finding the particle within an elemental volume dV is given by, a), , dV, , b), , dV, , c), , 2, , | dV, , d), , 2, , dV, , 16. When an electron is accelerated by a potential V, then its de Broglie wavelength is _________, 17. The de-Broglie wavelength of an electron which has been accelerated from rest on, application of potential of 400volts is ________________, 18. The Einstein s photoelectric equation is ______________, 19. The threshold wavelength of photoelectric emission of a metal is 4000Å. Then the minimum, energy required to eject photo electron is _____________, 20. In a photon-particle collision, the total energy and momentum are ____________, 21. The time independent Schrodinger equation for one dimensional motion _____________, 22. The waves associated with particles are known as __________, 23. The de Broglie wavelength of an electron whose kinetic energy is 100 eV ___________.

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UNIT-II, Multiple choice type questions:, 1., , How does a semiconductor behave at absolute zero?, a) Conductor, , 2., , b) Insulator, , b) Impurity concentration, , b) n-type semiconductor, , d) All, , c) p-type semiconductor, , d) insulator, , b) minority carriers, , c) electrons, , d) holes, , b) decrease, , c) becomes zero, , d)does not change, , Hall voltage is directly proportional to, a) Current, , 8., , c) Temperature, , On increasing current in a PN junction, the potential barrier will, a) Increase, , 7., , d) Charges, , The potential barrier opposes the flow of, a) majority carriers, , 6., , c) Holes, , If RH is negative for a certain material, then the material is a, a) Metal, , 5., , b) Electrons, , Fermi level for extrinsic semiconductor depends on, a) Donor element, , 4., , d) Protection device, , What are the charge carriers in semiconductors?, a) Electrons and holes, , 3., , c) Semiconductor, , b) electric field, , c) magnetic flux density, , d) All, , Which one of the following statements is not correct for a junction transistor?, a) The base region is very thin, , b) Emitter is heavily doped as compared, , c) Emitter and collector can be interchanged, , d) none, , 9. Choose the wrong statement. By measuring the hall coefficient one can calculate, a) Mobility of charge carrier, , b) concentration of charge carrier, , c) Type of semiconductor, , d) energy gap of the semiconductor, , 10. For an n-type semiconductor the Hall coefficient RH is related to carrier concentration n by, a) RH = - ne, , b) RH = - n/e, , c) RH = - e/m, , d) RH = - 1/ne, , 11. When PN junction is formed is a small region on either side of the junction an electric field, appears. This region is called ____________, 12. A semiconductor has _____________ temperature coefficient of resistance, 13. A device which converts alternating current (a.c) to direct or unidirectional current (d.c) is, called as _______________, 14. Under forward bias condition PN junction diode offers _________resistance, 15. Under reverse bias condition PN junction diode offers __________resistance.

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16. The thickness of depletion region is in the order of __________, 17. If b is the width of the sample, VH the Hall voltage developed when placed in magnetic field, of induction B, and current I flow through it, then Hall coefficient is given by__________., 18. Recombination takes place when an electron falls into a ________________, 19. The most occupied energy level at absolute zero is called -------------level., 20. The majority charge carriers in p-type semiconductor are------------., , UNIT-III, Multiple choice type questions:, 1. GaAs is _________________________semiconductor, a) direct band gap, , b) indirect band gap, , c) electric band gap, , d) electronic band gap, , 2. Ge is___________________semiconductor., a) direct band gap, , b) indirect band gap, , c) electric band gap, , d) electronic band gap, , 3. In LED, the band gap is 1.24ev, the emitted light wavelength is_______________Å., a) 1000, , b) 5000, , c) 8000, , d) 10000, , 4. LED is always operated in ________________bias, a) In all, , b) reverse, , c) forward, , d) none, , 5. If a PN junction operated under forward bias gives rise to injection luminescence, then it is called ________, a) Photo diode b) semiconductor laser c) LED d) solar cell, 1. The relation between band gap of semiconductor and emitted light wavelength is----2. The intrinsic semiconductor behave as insulator at --------K, 3. LED stands for----------------------------------------4. The recombination of an electron and hole in a direct band gap semiconductor result ----energy., 5. The band gap of LED material is 10 ev , it emitted light wavelength is------ A0

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mid-2, applied physics, question bank, , Note:, , ****, , very important question, , ***, , Important question, , **, , Rarely asked question

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UNIT-III, OPTO-ELECTRONICS, , S.No., , Question, , ****1. a) What is solar cell?, b) Explain Fill factor of Solar Cell., c) Explain the Construction, working and, characteristic curve of solar cell., **2., a) Write the working principle of photodiode., b) List out applications of photodiode and define, quantum efficiency of photo diode., c) Explain the construction, working and, characteristic curve of photodiodes., ***3, a) Write working principle of semiconductor laser., , **4., , b) write difference between Semi conductor laser, and LED., c) Explain the construction and working of, Semiconductor laser., a) Explain working principle of PIN diode, b) list out applications of PIN diode and avalanche, diode, c) Explain construction and working of avalanche, diode and PIN diode., , Marks, , CO, , PO, , BTL, , 2M, 3M, 10M, , 3, 3, 3, , 1-8,10,12, 1-8,10,12, 1-8,10,12, , I,II, II, IV, , 2M, 3M, , 3, 3, , 1-8,10,12, 1-8,10,12, , 10M, , 3, , 1-8,10,12, , II, I, &IV, IV, , 2M, , 3, , 1-8,10,12, , II, , 3M, , 3, , 1-8,10,12, , IV, , 10M, , 3, , 1-8,10,12, , IV, , 2M, 3M, , 3, 3, , 1-8,10,12, 1-8,10,12, , II, IV, , 10M, , 3, , 1-8,10,12, , IV, , a), ************************************

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UNIT-4, LASERS AND OPTICAL FIBER, (Compulsory chose one question from each topic), , S.No., , Question, , TOPIC -1 LASER, ****1. a) What are the characteristics of laser, b) Explain about various pumping methods., c) Explain the construction, working and, applications of Ruby laser., ****2. a) Write the difference between laser source and, ordinary light source., b) Explain about population inversion and optical, resonator., ****3., , ***4., , ****1, , ***2., , **3., , Marks, , CO, , PO, , BTL, , 2M, 3M, 10M, , 4, 4, 4, , 1-8,10,12, 1-8,10,12, 1-8,10,12, , I, II, IV, , 2M, , 4, , 1-8,10,12, , IV, , 3M, , 4, , 1-8,10,12, , II, , c) Explain the construction, working and application of, He-Ne laser., a) Write difference between stimulated and, spontaneous emission., , 10M, , 4, , 1-8,10,12, , IV, , 2M, , 4, , 1-8,10,12, , IV, , b) Explain about Laser action., c) Explain the construction,working and, applications of Carbon dioxide laser., a) Define coherence., b) Explain induced absorption and stimulated, emission., c) Obtain the relation between Einstein coefficients., , 3M, 10M, , 4, 4, , 1-8,10,12, 1-8,10,12, , II, IV, , 2M, 3M, , 4, 4, , 1-8,10,12, 1-8,10,12, , I, III, , 10M, , 4, , 1-8,10,12, , VI, , 4, 4, 4, , 1-8,10,12, 1-8,10,12, 1-8,10,12, , 4, 4, , 1-8,10,12, 1-8,10,12, , II, II, I&, VI, I, II, , 4, , 1-8,10,12, , IV, , 4, , 1-8,10,12, , IV, , 4, , 1-8,10,12, , VI, , 4, , 1-8,10,12, , III, , TOPIC 2- FIBER OPTICS, a) Write the principle of optical fiber., 2M, b) Explain the structure of optical fiber., 3M, c) Define and derive Numerical aperature and, 10M, acceptance angle of optical fiber., a) Define attenuation., 2M, b) Explain about application of optical fiber in, 3M, communications., c) Write the difference between step index and, 10M, graded index fiber and single mode and multimode, optical fiber, a) Compare copper coaxial cable and optical fiber, 2M, cable., b) Obtain the relation between Numerical aperature 3M, and ratio of refractive index., c) Explain about fiber loses and applications of, 10M, optical fiber in medical field., , **************************************

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UNIT 4- PROBLEMS, (Choose only one problem from this list), , S.No., 1, 2, 3, , 4, , 5, , Question, Calculate the wave length of the emitted radiation, from GaAs which has band gap of 1.44eV., A semiconductor diode laser has a peak emission, wavelength of 1.55μm. Find its band gap in ev., An optical fiber has a core material of refractive, index of 1.55 and cladding material of refractive, index of 1.50. The light is launched into it in air., Calculate its numerical aperture., The numerical aperture of and optical fiber is 0.39. if, the difference in the refractive indices of a material, of core and cladding is 0.05, calculate the refractive, index of the material of the core., He-Ne laser wavelength 6328A has an output power, of 2.3 mW. How many photons emitted each minute, when it is operated., , Marks CO, , PO, , BTL, , 2M, , 4, , 1-8,10,12, , V, , 3M, , 4, , 1-8,10,12, , V, , 3M, , 4, , 1-8,10,12, , V, , 3M, , 4, , 1-8,10,12, , V, , 3M, , 4, , 1-8,10,12, , V

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UNIT – V, ELECTROMAGNETISM, DILECTRIC & MAGNETIC PROPERTIES, (Compulsory chose one question from each topic), , S.No., , Question, , Marks, , TOPIC-1 ELECTROMAGNETISM, a) State ampere’s law and Faraday’s law, 2M, 3M, b) Derive continuity equation., c) Explain the differential and integral form of, 10M, Maxwell’s equations., TOPIC 2- DIELECTRICS, ****2. a) Define electric dipole and electric, 2M, polarisation., b) Explain about various polarizabilities., 3M, c) Derive the expression for internal field and, 10M, ***1., , CO, , PO, , BTL, , 5, 5, 5, , 1-8,10,12 I, 1-8,10,12 VI, 1-8,10,12 V, , 5, , 1-8,10,12 I, , 5, 5, , 1-8,10,12 II, 1-8,10,12 VI, , clasius-mossotti equation., , ***3., , a) Define electric susceptibility and, 2M, 5, permittivity., b) Obtain the relation between electrical, 3M, 5, susceptibility and permittivity., c) Explain about ferroelectrics and, 10M 5, piezoelectrics, TOPIC 3- MAGNETIC MATERIALS, **4., a) Define magnetic susceptibility and, 2M, 5, permeability., b) Obtain the relation between B,H and M., 3M, 5, c) Explain about classification of magnetic, 10M 5, materials., ****5. a) Define magnetic induction and magnetic, 2M, 5, field., b) Obtain the relation between magnetic, 3M, 5, susceptibility and permeability., c) Write note on domain theory and explain, 10M 5, Hysteresis curve based on domain concept and, write difference between soft and hard magnetic, materials., **************************************, , 1-8,10,12 I, 1-8,10,12 IV, 1-8,10,12 II, 1-8,10,12 I, 1-8,10,12 III, 1-8,10,12 IV, 1-8,10,12 I, 1-8,10,12 III, 1-8,10,12 I,III&IV

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UNIT 5-PROBLEMS, (Choose only one problem from this list), S.No., 1, , 2, 3, 4, , 5, 6, , 7, , 8, , Question, A magnetic material has a magnetization of 3300, ampere / m and flux density of 0.0044 wb / m2 ., Calculate the magnetizing force and the relative, permeability of the material., A paramagnetic material has magnetic field intensity, 2X104A/m. If the Susceptibility of the material is, 3.0X 10-4.Calculate the flux density., Find the electric susceptibility of a dielectric gas, having dielectric constant of 1.000041., For a paramagnetic material the susceptibility at, 340K is 1.76 X 10-4.Calculate its susceptibility at, 310K., , Marks CO, PO, 3M, 5, 1-8,10,12, , BTL, V, , 3M, , 5, , 1-8,10,12, , V, , 3M, , 5, , 1-8,10,12, , V, , 3M, , 5, , 1-8,10,12, , V, , The magnetic susceptibility of aluminum is, 2.3X10-5.Find its permeability and relative, permeability., If a magnetic field of strength 300amp/meter, produces a magnetization of 4200A/m in a, ferromagnetic material .Find the relative, permeability of the material., , 3M, , 5, , 1-8,10,12, , V, , 3M, , 5, , 1-8,10,12, , V, , The magnetic field strength in silicon is 1000 p/m. If, the magnetic field susceptibility is -0.3 A 10 -5 ,, Calculate the magnetization and flux density in, silicon., A paramagnetic material has 10 28 atoms per m3.Its, susceptibility at 350K is 2.8X 10-4.Calculate the, susceptibility at 300K, , 3M, , 5, , 1-8,10,12, , V, , 3M, , 5, , 1-8,10,12, , V

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mid-2, applied physics, question bank, , Note:, , ****, , very important question, , ***, , Important question, , **, , Rarely asked question

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UNIT-III, OPTO-ELECTRONICS, , S.No., , Question, , Marks, , ****1. a) What is solar cell? Explain the construction, 8M, working and characteristic curve of solar cell, b) Explain Fill factor of Solar Cell and write, 7M, applications of solar cell., **2., a) Write the working principle of photodiode. 8M, Explain the construction, working and characteristic, curve of photodiodes., b) List out applications of photodiode and define 7M, quantum efficiency of photo diode., ***3, a) Write working principle of semiconductor laser. 8M, Explain the construction and working of, Semiconductor laser., b) write difference between Semi conductor laser, 7M, and LED., **4., a) Explain working principle of PIN diode and list 7M, out applications of PIN diode and avalanche diode, b) Explain construction and working of avalanche, 8M, diode and PIN diode., a), ************************************, , CO, , PO, , BTL, , 3, , 1-8,10,12, , I,II, , 3, , 1-8,10,12, , II,IV, , 3, , 1-8,10,12, , II,IV, , 3, , 1-8,10,12, , 3, , 1-8,10,12, , I, &IV, II,IV, , 3, , 1-8,10,12, , IV, , 3, , 1-8,10,12, , II,IV, , 3, , 1-8,10,12, , IV

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UNIT-4, LASER AND OPTICAL FIBER, S.No., , Question, TOPIC -1, , Marks, , CO, , PO, , BTL, , LASER, , ****1. a) What are the characteristics of laser and Write, , 7M, , 4, , 1-8,10,12, , I, , 8M, , 4, , 1-8,10,12, , IV, , 7M, , 4, , 1-8,10,12, , IV, , 8M, , 4, , 1-8,10,12, , IV, , 7M, 8M, , 4, 4, , 1-8,10,12, 1-8,10,12, , IV, IV, , a) Explain structure and principle optical fiber., 7M, 4, b) Define and derive Numerical aperature and, 10M, 4, acceptance angle of optical fiber., a) Define attenuation and explain about fiber loses. 7M, 4, c) Write the difference between step index and, 8M, 4, graded index fiber and single mode and multimode, optical fiber, **************************************, , 1-8,10,12, 1-8,10,12, , II, I&, VI, I,IV, IV, , difference between stimulated and spontaneous, emission, , b) Explain the construction, working and, applications of Ruby laser., ****2. a) what is pumping? Explain various pumping, methods., ****3., , b) Explain the construction, working and application of, He-Ne laser., a). Obtain the relation between Einstein coefficients., , b) Explain the construction,working and, applications of Carbon dioxide laser., TOPIC 2- FIBER OPTICS, ****1, , ***2., , 1-8,10,12, 1-8,10,12

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UNIT – V, ELECTROMAGNETISM, DILECTRIC & MAGNETIC PROPERTIES, S.No., , Question, , Marks, , CO, , ****2, , TOPIC-1 ELECTROMAGNETISM, a) State ampere la , Farada la and, 7M, 5, Derive continuity equation, c) Explain the differential and integral form of, 8M, 5, Ma ell eq a ion ., TOPIC 2- DIELECTRICS, c) Derive the expression for internal field and, 15M 5, , ***3, , clasius-mossotti equation., a ) Explain about various polarizabilities, , ***1., , 7M, 8M, , 5, 5, , b) Explain about ferroelectrics and, piezoelectrics, TOPIC 3- MAGNETIC MATERIALS, **4., a) Obtain the relation between B,H, and M (or I), 7M, 5, b) Explain about classification of magnetic, 8M, 5, materials., ****5. a) what is domain theory and explain Hysteresis, 7M, 5, curve, b) Write the differerence between soft and hard, 8M, 5, magnetic materials.., **************************************, , PO, , BTL, , 1-8,10,12 I,VI, 1-8,10,12 V, 1-8,10,12 VI, 1-8,10,12 IV, 1-8,10,12 II, 1-8,10,12 III, 1-8,10,12 IV, 1-8,10,12 I, 1-8,10,12 III,IV

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APPLIED PHYSICS BIT BANK, UNIT-III, Multiple choice type questions:, 1. Photo diode is always operated in _____________bias., a) In all, , b) reverse, , c) forward, , d) none, , 2. GaAsP laser source emits ____________colour., a) Green, , b) red, , c) white, , d) blue, , 3. Fill factor of solar cell lies between__________and _____________., a) 0.1, 0.3, , b) 0.7, 0.8, , c) 0, 1, , d) 0.2, 0.3, , 4. The power efficiency of solar cell is__________, a) 50%, , b) 25%, , c) 15%, , d) 10%, , 5. The main material used in the construction of PIN diodes is -------a) GaAs, , b) Si, , c) Ge, , d) Se, , 1. Current gain of ------------------diode is higher., 2. The number of junctions in PIN diode-------3. The function of the photodiode is the opposite of ------------diode., 4. The Formula of Fill factor of solar cell is ------5. The Formula of Quantum efficiency of photo diode is -----6. The current in the photo diode in the absence of incident light is called ---------current., , UNIT-IV, Multiple choice type questions:, 1. Propagation of light through fiber core is due to, a) Diffraction, , b) Interference, , c) Total internal reflection, , d) refraction, , 2. Step index fiber can be a, a) Monomode fiber only, , c) Monomode as well as multimode fiber, , b) Multimode fiber only, , d) Either monopod or multimode (cannot be both)

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3. Single mode fiber supports, a), , Meridinal rays only, , c) Meridinal rays as well as skew rays, , b), , Helical rays, , d) Meridinal, skew as well as helical rays, , 4. The process of mixing the signal with the carrier is called, a) Dispersion, , b) attenuation, , c) modulation, , d) demodulation, , 5. In a fiber if the output signal is 50mW for an input of 100 m W the loss in dB of length 1 meter is, a) 0.5, , b) 3, , c) 2, , d) 50, , 6. The attenuation in the optical fiber is a function is, a) Fiber material only, , b) Wavelength of light only, , c) Length of fiber only d) All the above, 7. The losses induced because of Rayleigh scattering, a), , vary inversely with the fourth power of the wavelength, , b), , vary directly with the fourth power of the wavelength, , c), , Vary inversely with the second power of the wavelength, , d), , Vary directly with wavelength, , 8 Total internal reflection takes places when light ray travel from, a) Denser to rarer medium, , b) Denser to denser medium, , c) Rarer to rarer medium, , d) Rarer to denser medium., , 9. The source of excitation in ruby laser is, a) Sodium vapor lamp, , b) xenon flash lamp, , c) Mercury vapor lamp, , d) incandescent lamp, , 10. In single mode fiber optic communication system, the preferable source of light is, a) LED, , b) sodium lamp, , c) mercury lamp, , d) laser, , 11. The condition for laser action is, a) Excitation b) meta-stable state, , c) population inversion, , d) emission, , 12. The wavelength emitted by He-Ne laser is, a) 623.8nm, , b) 632.8nm, , c) 682.3nm, , d) 683.2nm, , 13. The refractive index of core is 1.5. The refractive index of cladding can be, a) 1.52, , b) 1.55, , c) 1.60, , d) 1.45

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14. In an optical fiber, meridional rays propagate, a) Along the walls of the fiber, , b) along the axis of the fiber, , c) Into the cladding material, , d) along the cladding of the fiber., , 15. Which of the following system does not produce lasing action, a) Two level system, , b) Three level system, , c) Four level system, , d) five level system, , 16. High power laser light obtained from, a) Carbon dioxide laser, , b) Ruby laser, , c) Semiconductor laser, , d) He-Ne laser, , 17. He-Ne laser is -----------level system., 18. In ruby lasing material the percentage of chromium ions in aluminum oxide is ------19. Pumping method of He-Ne laser---------20. In He-Ne laser, He:Ne ratio is-----------21. Ruby laser is ----------level system., 22. When the population of the excited state is larger than the population of the lower state, the, condition is called----------23. In which state the atoms relax much more time, that level is called---------24. Propagation of light through optical fibre is due to---------------25. In optical fibre the refractive index of core is--------------than refractive index of cladding., 26. The e, , e ion fo n me ical a e, , ei, , .., , 27. The maximum gathering power of light by optical fibre is called-------------28. In semiconductor laser pumping method is---29.The emission of photon when an electron jumps from higher energy state to lower energy state due, to interaction of external energy is called-------- --------, , emission, , 30. The pumping method of ruby laser is---31. In ruby lasing material the percentage of chromium ions in aluminum oxide is ------------32. The condition for laser action is--------------33. In ruby laser, the laser action is due to-----------------ions

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UNIT-V, Multiple choice type questions:, 1. The material in which spontaneous polarization changes with mechanical pressure is called, a) ferro electric, , b) pyro electric, , c) piezo electric, , d) anti-ferromagnetic, , 2. The magnetic susceptibility of the magnetic material is given by, a), , +1, , b), , 1, , 1, , c), , /1, , d), , -1, , 3. The relation between magnetic induction (B) and magnetic field strength (H) and magnetization, (M)is, a) B=H+M, , b) B=M+ H, , c) B=, , (H+M), , d) M=B+ H, , 4) The temperature at which the susceptibility becomes maximum for anti ferro magnetic materials, is, called, a) curie temperature, , b) Debye temperature, , c) curie- Weiss temperature, , d) Neel temperature., , 5. Polarization per unit electric field is called, a) Electric susceptibility, , b) magnetic susceptibility, , c) Electric polarizability, , d) dielectric constant, , 6. Magnetization per unit magnetic field intensity is called, a) Magnetic induction, , b) magnetic susceptibility, , c) Magnetic permeability, , d) magnetic flux density, , 7. Diamagnetic susceptibility is, a) large, negative, , b) small, positive, , c) small , negative, , d) large,positive, , 8. Single pole magnetic does not exist in nature is explained as, , 9. ∇. J, , a) ∇, , b) ∇., , c) ∇ 𝐵, , d) ∇. 𝐵, , 0, , 0 is, , a) Am e e la, , b) Fa ada, , la, , c) Continuity equation for fields, , d) continuity equation for steady current, , 10. Above Curie temperature Ferro magnetic material changes to, a) dia, , b) para, , c) anti ferro, , d) ferri

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1. In anti-ferromagnetic , the magnetic dipoles of the adjacent atoms are___________, 2. The units of magnetic dipole moment is _____________, 3. The units of magnetic induction is___________________, 4. The unit of magnetic flux is______________________, 5. The unit of susceptibility is______________________, 6. The susceptibility of diamagnetic material is ___________ of temperature, 7. Equal number of opposite spins with different magnitude present in -----material., 8. The temperature at which the susceptibility becomes maximum for anti-ferromagnetic, materials is called______________________, 9. Clausius-mossoti equation is________________, 10. The expression for local electric field is______________________

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UNIT-1, PREVIOUS YEAR EXAM QUESTIONS, VSAQ, 1. What is meant by Black body? Give an example. Write the equation for energy, density in case of black body from Plank s law., 2. Define a) Photoelectric effect b) Threshold frequency c) work function., 3. What is Compton Effect and write equation for Compton shift?, 4. Define matter waves. Write the properties of matter waves., 5. What is the significance of wave function, , ., , 6. State Heisenberg s uncertaint principle., 7. Write equations for Eigen value and Eigen function for a particle in onedimensional potential box., 8. What is Photo-electric effect and write the Einstein s equation., , SAQ, 1. Explain the concept of Black body radiation., 2. Explain the phenomenon of photo-electric effect with suitable example., 3. What is Compton Effect and explain?, 4. What is the de-Broglie wavelength for moving matter? Derive equation for deBroglie wavelength of electron., 5. Derive Schrodinger s time independent wave equation., 6. When light of wavelength 300nm is incident on Potassium, the emitted, electrons have maximum kinetic energy of 1.91eV. (i) What is the energy of, incident photons? (ii) What is the work function for Potassium?

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7. When light of wavelength 300nm is incident on Potassium, the emitted, electrons have maximum kinetic energy of 1.91eV. (i) What is the energy of, incident photons? (ii) What is the work function for Potassium?, 8. X-rays of wavelength 10pm are scattered from a target. (i) Find the wavelength, of the X-rays scattered through 45 degrees. (ii) Find the maximum wavelength, present in the scattered X-rays. (iii) Find the maximum Kinetic energy of the, recoil electron., 9. If the kinetic energy of the neutron is 0.025eV, calculate its de-Broglie, wavelength., 10. An electron is bound in one-dimensional infinite well of width 10-10m. Find, the energy values in the ground state and first two excited states., 11. Explain the significance of Quantum Mechanics., , LAQ, 1. Explain the phenomenon of Black bod radiation and derive Plank s law of, Black body radiation., 2. Explain photo-electric effect in detail., 3. Explain Compton effect and derive equation for Compton shift., 4. Explain construction and working of Davision - Germer experiment to prove, that the moving matter is associated with a wave., 5. Derive time independent Schrodinger wave equation., 6. Deduce equations for wave function and energy of the particle in a onedimensional potential box., 8. State and Explain Heisenberg s principle with the suitable application.

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UNIT-II -SEMICONDUCTOR PHYSICS, PREVIOUS YEAR EXAM QUESTIONS, VSAQ, 1. Distinguish between P-N junction diode and Zener diode., 2. Explain the importance of Hall effect, 3. Describe direct and indirect band gap semiconductors, 4. Draw I-V characteristic curve of a PN junction diode and explain?, 5. The Hall co-efficient of a specimen is 3.66 X 10-4 m3C-1. Its resistivity is, 8.93 X 10-3 Ohm m. Calculate mobility and electron carrier concentration., 6. Draw the diode symbol and explain any one of the breakdown mechanisms., 7. What is donors and acceptors give two examples for each., 8. What is reverse saturation current., 9. What is the importance of fermi level., 10. List out the applications of Hall Effect., , SAQ, 1. Distinguish between intrinsic and extrinsic semiconductors with suitable, examples., 2. Distinguish between n-type and p-type semiconductors., 3. What is Zener diode? Explain working of Zener diode., 4. Write a short note on drift current and diffusion current in the, semiconductors.

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5. Explain the carrier generation and recombination processes., 6. Explain fermi level dependence on carrier concentration., 7. The Hall coefficient of certain Silicon specimen was found to be, -7.35 X10-5 m3C-1 from 100K to 400K. Determine the nature of the, semiconductor. If the conductivity was found to be 200m-1 (ohm)-1. Calculate the, density and mobility of the charge carrier., 8. List out the application of BJT transistor., 9. Explain Zener and Avalanche breakdown., 10. How Zener diode is different to normal diode., , LAQ, 1. Derive an expression for carrier concentration of holes in intrinsic, semiconductor, 2. Derive an expression for carrier concentration of electrons in intrinsic, semiconductor, 3. Write a note on intrinsic semiconductors. Derive an expression for Fermi level, and carrier concentration in intrinsic Semiconductors., 4., , Derive an expression for the carrier concentration of an n-type, , semiconductor., , and how Fermi level varies with temperature and doping, , concentration., 5. Derive an expression for the carrier concentration of an p-type semiconductor., and how Fermi level varies with temperature and doping concentration., 6. State and explain the Hall Effect and explain the experimental method to, determine the Hall co-efficient and Hall voltage.

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7. What is bipolar junction transistor? Explain construction and principle of, operation of the bipolar transistor (n-p-n transistor)., 8. What is bipolar junction transistor? Explain construction and principle of, operation of the bipolar transistor (n-p-n transistor)., 9. Explain how PN junction is formed. Explain the working of PN diode in both, forward and reverse bias conditions and explain the energy level diagram of PN, junction., 10. With the neat diagram describe the V-I characteristics of Zener diode in both, the biased conditions.

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UNIT – III-OPTOELECTRONICS, PREVIOUS YEARS EXAM QUESTIONS, VSAQ, 1. Define radiative and non-radiative recombination mechanisms?, 2. A light emitting diode is made of GaAsP having band gap of 1.9ev. Determine, the wavelength of the radiation emitted?, 3. What is the principle of LED?, 4. What are applications of LED., 5. Write differences between semiconductor laser and LED?, 6. What are the differences between PIN and Avalanche photodiode?, 7. Illustrate about LED materials., , SAQ, 1. Explain about direct and indirect band gap semiconductors?, 2. Explain about homo junction and hetero junction semiconductors?, 3. Explain the V, , I characteristics of solar cell?, , 4. Explain the V, , I characteristics of LED?, , 5. Explain any two characteristics of PIN photo diode?, 6. Explain the avalanche photo diode?, 7. What is the photo diode? Write the various applications of photo diode?, 8. Distinguish between PIN diode and LED?, 9. What is recombination mechanism in semiconductors?

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10. What is a photodetector? Explain the principle of photo detection in, semiconductors., 11. When 3 × 1011 photons each, , ith, , avelength of 0.85 m are incident on a, , photodiode, on average 1.2 × 1011 electrons are generated. Determine the, quantum efficiency and responsivity., 12. A silicon photodiode has quantum efficiency of 65% with photon energy, 1.5×10-19 J. Its band gap energy is 0.67eV. Calculate:, ii) Incident po er required to obtain a photo current 2.5, , i) Responsivity (R), , A (Po)?, , 13. Illustrate working of p-i-n diode., 14. What is figure of merit of LED., , LAQ:, 1. Explain the radiative and non-radiative recombination mechanism in, semiconductors in detail?, 2. Explain recombination mechanism in Direct and indirect band gap, semiconductors?, 3. Explain the principle, construction and working of Semiconductor laser., 4. What is Photo detector. What are the major requirements of a photo detector, for a better performance? What are the sources of Noise in photodiode? State, the various figure of merit parameters used to assess the noise performance., 5. Explain principle, construction, working and V-I characteristics of LED., 5. Explain the construction and working of solar cell with neat diagram. State, few advantages and disadvantages of solar cell? Define the efficiency and fill, factor. Explain V-I characteristics of solar cell?, 6. Explain principle, construction, working and V-I characteristics of PIN diode?, 7. Explain principle, construction, working and V-I characteristics of Avalanche, photodiode?

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UNIT-4, PREVIOUS YEAR EXAM QUESTIONS, VSAQ, 1. What is the LASER? Explain its principle?, 2. What are the merits of a semiconductor LASER?, 3. How LASER beam achieves Coherence?, 4. Explain optical fiber as a dielectric wave guide?, 5. Derive an expression for Acceptance angle of an optical Fiber?, 6. Define the term Stimulated Absorption?, 7. Define the term Spontaneous Emission?, 8. Define the term Stimulated Emission?, 9. Define the term Population inversion?, 10. What are Pumping mechanisms in Lasers?, 11. Explain Total Internal Reflection?, SAQ, 1. Distinguish between the spontaneous emission and stimulated emission, processes of Light?, 2. What are the general characteristics of LASER?, 3. What do you understand by population inversion? How is it achieved?, 4. Explain different mechanisms to pump atoms to create population inversion?, 5. Derive the relationship between Einstein coefficients?

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6. Explain Total internal reflection concept. How it will be useful in an optical, fiber?, 7. Explain the structure and principle of an optical fiber?, 8. Explain Acceptance angle and Numerical aperture?, 9. Differentiate graded index fibers from step index fibers?, 10. Write the differences between single mode and multi-mode optical fiber., 11. Describe graded index fiber and explain the transmission of signal through, it?, 12. Find the numerical aperture and acceptance angle of a fiber of a core index, 1.4 and fractional refractive indices of 0.002?, 13. Calculate Numerical Aperture of a material with acceptance angle of 60, degree in water?, 14. Explain the dispersion losses in optical fiber?, 15. An Optical fiber has numerical Aperture of 0.2 and a cladding refractive index, of 1.59. Find the acceptance angle for the fiber in water of refractive index 1.33?, , LAQ, 1. Explain the construction of ruby LASER. How it is different from He-Ne, LASER?, 2. With neat diagram explain principle, construction and working of Ruby, LASER?, 4. With neat energy level diagram explain the construction and working of a, Helium Neon LASER?, 5. Explain the principle and working of a Carbon dioxide LASER?

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6. Explain the applications of lasers in various fields?, 7. Describe the characteristics of optical fiber based on refractive index?, 8. Derive an expression for acceptance angle for an optical fiber. How is it related, to Numerical aperture?, 9. Draw and explain the block diagram of fiber optical communication system?, 10. What are the Applications of optical fibers?, 11. Explain various losses (attenuations) in optical fiber communication.

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UNIT-5, PREVIOUS YEARS EXAM QUESTIONS, VSAQ, 1. State Coulomb s law and write the expression for electrostatic force between, two-point charges., 2. Write expressions for Gauss, Ampere and Faraday s laws., 3. Define Polarization and Polarizability., 4., , Define, , the, , terms, , Magnetic, , induction,, , magnetization,, , and, , magnetic, , susceptibility., 5. Write the differences between Para, Ferro, Ferri and Anti-ferro magnetic, materials., 6. Obtain the relation between B,H and M., 7. Define dielectric constant., 8. Why the susceptibility of dia magnetic material is negative., 9. State Faraday s law., , SAQ:, 1. What are laws of electrostatics?, 2. Write differential and integral forms of Maxwell equations., 3. Explain about various polarizabilities., 3. Derive the expression for Clausius-Mossoti equation., 4. Write note on piezo electricity.

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5. Write note on Ferro electricity., 6. Write note on Pyro electricity., 7. Write the differences between soft and hard magnetic materials., 8. What is the significance of permeability in magnetic materials?, 9. Show that P =, 10. Show that, , r, , oE( r, , -1)., , = 1+, , 11. What is the internal field in dielectric material? Give an expression for, Claussius-Mossotti relation., 12. Write a short note on ionic polarization and orientational polarization., , LAQ:, 1. Derive Gauss, Ampere, Faraday laws., 2. Derive equation of continuity., 3. Derive expression for local field (Lorentz method) for a cubic dielectric crystal, and Deduce Clausius-Mossotti equation., 4. Define magnetic moment. Explain origin of magnetic moment in detail., 5. Explain Domain theory and Hysteresis curve based on domain theory., 6. Describe classification of magnetic materials in detail., 7. Define electronic polarizability and derive equation for electronic polarizability.

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TOPIC WISE PROBLEMS, UNIT-1, Photon, 1. The wavelength of yellow light is 6000 A . What is the energy of the photon?, 2. The band gap of semiconductor is 1.2 eV. Calculate the emitted light wave length., Number of photons, 1. A blue lamp emits light of mean wavelength 5000 A. The lamp is rated 150W.How, many photons emitted per second by the lamp?, 2. A Led emits light of wave length 5000 A. The source is rated 10W and 10% of the, energy appears as light. How photons emitted per hour., Photo electric effect, 1. Light of wavelength 2000 A falls on an aluminum surface with work function, 4.2eV. Calculate 1) threshold wavelength 2) stopping potential 3) kinetic energy of, emitted electron4) velocity of emitted electron., 2. Light of wavelength 2000 A falls on photo metal, the stopping potential is 2V,, calculate its work function., Compton Effect, 1. X-rays of 0.5A are scattered by free electrons in a block of carbon through 90., Find the velocity recoil electrons., 2. Photon of initial energy 90 keV undergoes Compton scattering at an angle 60,, find 1) the energy of the scattered photon 2) the recoil energy of the electron.

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Uncertainty principle, 1. Uncertainty in time of an excited atom is about 10, , -8, , sec. what are the, , uncertainties in energy and in frequency of the radiation., 2. An electron is confined to a potential well of width 10nm.Calculate the minimum, uncertainty in its velocity., 3. An electron and a 150 gm baseball are travelling at a velocity of 220m/s measured, to an accuracy of 0.005%. Calculate and compare uncertainty in position of each, 4. Using the Heisenberg’s Uncertainty principle explain why electron cannot exist, -14m., in the Nucleus of radius 10, particle in 1 D box, 1. An electron is confined to move in a one dimensional potential well of length, 5A.Find the quantized energy values for the three lowest energy states., 2. For an electron in a one-dimensional infinite potential well of width 1A0,, calculate the energy separation between the two lowest energy levels and also, calculate the frequency and wavelength of the photon corresponding to a, transition between these two levels., de-Broglie waves, 1. Compute the de Broglie wavelength of an electron whose kinetic energy is 100eV., 2. An electron and a photon have the same non-relativistic kinetic energy. Show, that the proton has a shorter de Broglie wave length., 3. Calculate the de Broglie wavelength associated with a proton moving with a, velocity of 1/10 th of velocity of light., 4. Calculate the de Broglie wavelength of an electron which has been accelerated, from rest on application of potential of 400 volts., 5. Calculate the velocity and kinetic energy of an electron of wave length is, 1.66X10, , -19m.

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UNIT 2, Hall Effect, 1. A silicon plate of thickness 1 mm, breadth 10mm and length 100mm is placed in, a magnetic field of 0.5 wb/m2 acting perpendicular to its thickness. If 10 -2 A current, flows along its length. Calculate the Hall voltage developed if the Hall coefficient is, 3.66 X 10, , -4, , m3/coulomb, , 2. if RH of a specimen is 3.66X 10, , -4, , m3/c. its resistivity is 8.93 X 10 -3 ohm-m. Find, , n and mobility., 3. A current of 50 A is established in a slab of cu 0.5cm thick and 2cm wide. The, slab is placed in a magnetic field B of 1.5 T. The magnetic field is perpendicular to, the plane of the slab and to the current. The free electron concentration in copper, is 8.48 X 10, , 28, , electron /m3. What will be the magnitude of Hall voltage across the, , width of the slab?, 4. A rectangular plate of a semiconductor has dimensions 2.0 cm along y direction,, 1.0 mm along z-direction. Hall probes are attached on its two surfaces parallel to, x z plane and a magnetic field of 1.0 tesla is applied along z-direction. A current, of 3.0 mA is set up along the x direction. Calculate the hall voltage measured by, the probes, if the hall coefficient of the material is 3.66 X 10–4m3/C., , Also,, , calculate the charge carrier concentration., Drift and diffusion, 1. The intrinsic carrier density at room temperature in Ge is 2.37X10, , 19, , /cm3.if the, , electron and hole motilities are 0.38 and 0.18 m2Vs respectively, calculate the, resistivity., 2. The conductivity of N-type Germanium semiconductor is 39 Ω-1m-1. If the, mobility of electrons in Germanium is 0.39 m2V-1s-1, then find the concentration, of the donor atoms.

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Semiconductor, 1. The forbidden gap in pure silicon is 1.1 ev. Compare the number of conduction, electrons at temperature 37C and 27C, 2. For silicon semiconductor with bandgap 1.22 eV, determine the position of the, fermi level at 300K if mh/me=2, 3. For an intrinsic semiconductor with gap width E=0.7eV, calculate the, concerntration of intrinsic charge carriers at 300k assuming mh=me

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UNIT 3, Photo diode, 1. When 3 × 1011 photons each with wavelength of 0.85µm are incident on a, photodiode, on average 1.2 × 1011 electrons are generated. Determine the quantum, efficiency and responsivity., 2. A silicon photodiode has quantum efficiency of 65% with photon energy, 1.5×10-19 J. Its band gap energy is 0.67eV. Calculate:, i) Responsivity (R), ii) Incident power required to obtain a photo current 2.5 µA (Po)?., 3. A He-Ne gas laser of wavelength, , 6328 Å has an output power of 2.3 mW., , How many photons are emitted each minute when it is operated?, 4. The numerical aperture of an optical fiber is 0.5 and core refractive index, 1.54., , i) Find refractive index of cladding; ii) Calculate the change in core, , cladding refractive index per unit refractive index of the core.

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UNIT 4, Method 1(laser), 1. Find the relative population of the two states in a ruby laser that produces a light, beam of wavelength 6943A at 300k., 2. For a He-Ne laser at 1m and 2m distances from the laser the output beam spot, diameter are 4mm and 6mm respectively. Calculate divergence., 3. Calculate the wavelength of emitted radiation from GaAs which has a band gap, of 1.44eV., 4. A semiconductor diode has a peak emission wavelength of 1.55micro meters., Find the band gap in ev., OPTICAL FIBER, Method 1, 1. An optical fiber a core material of refractive index of 1.55 and cladding material, of refractive index of 1.50. The light is launched into it in air. Calculate numerical, aperture and acceptance angle., 2. Calculate the refractive indices of core and cladding of an optical fiber with a, numerical aperture of 0.33 and their fractional difference of refractive indices being, 0.22., 3. An optical fiber has numerical aperture of 0.20 and a cladding refractive index of, 1.59 .find the acceptance angle for the fiber in water which has a refractive index of, 1.33., 4. Calculate the fractional index change for a given optical fiber if the refractive, indices of the core and the cladding are 1.563 and 1.498., 5. A signal of 100mW is injected into a fiber. The out coming signal from the other, end is 40 mW. What is the loss in dB.

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UNIT 5, DIELECTRICS, 1. A parallel plate condenser has a capacitance of 2microfarad. The dielectric has, permittivity 100 .For an applied voltage of 1000V. Find the energy stored in the, condenser as well as the energy stored in polarization the dielectric., 2. a parallel plate capacitor having a plate separation of 2X10-3 m across which a, potential of 10V is applied. Calculate the dielectric displacement, when a material, of dielectric constant 6 is introduced between the plates., 3. A parallel capacitor has an area of 100 cm3, a plate separation of 1cm and is, charged to a potential of 100V. Calculate the capacitance of the capacitor and the, charge on the plates., Method 2, 1. a solid element dielectric with density 3X1028 atom/m3 shows an electronic, polarizability of 10, , -10, , farad m2 .Assuming the internal electric field to a Lorentz, , field , calculate the dielectric constant of the material., 2. The dielectric constant of He gas is 1.0000684. Calculate the electronic, polarizability of He atoms if the gas constants 2.7X10, , 25, , atoms per m3, , MAGNETIC MATERIALS, Method1, 1. The magnetic field in the interior of a certain solenoid has the value of 6.5x10, , -4, , T. when the solenoid is empty. When it is filled with iron, the field becomes 1.4 T., Find the relative permeability of iron., 2. Find the relative permeability of a ferromagnetic material if a field of strength 220, amp- m[/meter produces a magnetization 3300amp/meter in it.

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3. The magnetic field intensity in a piece of ferric oxide is 10, susceptibility of the material is 1.5 X 10, , -3., , 6, , amp/meter, if the, , Calculate the magnetization of the, , material and the flux density., Method 2, 1. A circular loop of copper having a diameter of 10cm carriers a current of 500mA., Calculate the magnetic associated with the loop., 2. a Paramagnetic material has 10, X 10, , -4.calculate, , 28, , atoms per m3, if susceptibility at 300K is 2.8, , the susceptibility at 300k