Engineering Physics B.Tech Question Paper : vardhaman.org
College : Vardhaman College Of Engineering
Degree : B.Tech
Semester : I
Subject : Engineering Physics
Document type : Question Paper
Website :vardhaman.org
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Engineering Physics Question Paper :
VARDHAMAN COLLEGE OF ENGINEERING
(AUTONOMOUS)
B. Tech I Semester Supplementary Examinations July – 2014
(Regulations : VCE-R11A)
(Common to Electronics and Communication Engineering, Electrical and Electronics Engineering & Mechanical Engineering)
Related : Vardhaman College Of Engineering Chemistry B.Tech Question Paper : www.pdfquestion.in/6287.html
Answer ONE question from each Unit
All Questions Carry Equal Marks
All parts of the question must be answered in one place only
Unit – I :
1. a) Explain with a suitable graph the variation of potential energy with interatomic distance. Derive an expression for cohesive energy of a diatomic molecule. 9M
b) What are the general properties of ionic bonds? With suitable examples, distinguish between ionic and covelent bonds. 6M
2. a) Calculate the atomic packing fraction of f.c.c. and diamond crystal structures with schematic diagrams. 9M
b) Distinguish between unit cell and primitive cell. Explain the structure of ZnS. 6M
Unit – II :
3. a) Outline the procedure for determining Miller indices of a crystal plane. With neat diagram obtain an expression for inter planar spacing of an orthogonal crystal system. 9M
b) Explain powder crystal method for determination of crystal structures. 6M
4. a) What is the importance of surface to volume ratio in nano scale. Explain how the properties depend on the S/V ratio. 7M
b) Discuss Sol-gel method for nano material synthesis. What are its advantages? 8M
Unit – III :
5. a) Explain Debroglie’s hypothesis. Derive an expression for Schrodinger’s time independent wave equation. 10M
b) 10 keV electrons are passed through a thin film of a metal for which atomic spacing is 5.5 ×10-11 m. Calculate the glancing angle for the first order maximum. 5M
6. a) State Bloch’s theorem. What are the salient features of Kronig Penney model? How does this model explain the energy band formation in solids? 10M
b) What are the characteristics of a wave function representing matter waves? Explain the physical significance of the wave function. 5M
Unit – IV :
7. a) What is the origin of internal fields in dielectric materials? Derive the Clausius-Mossotti equation for a dielectric. 8M
b) Define dielectric polarization and susceptibility. Two parallel plates have equal and opposite charges and are separated by 5mm thick, of dielectric constant 3. The area ofthe plates is 1 cm2 and a potential difference of 5kV is applied between the plates. Calculate the capacitance of capacitors and electric field intensity. 7M
8. a) Explain BCS theory of super conductors. 9M
b) Explain Meissner effect. Mention three applications of super conductors. 6M
Unit – V :
9. a) Explain absorption, spontaneous emission, stimulated emission and population inversion with schematic diagrams. 8M
b) Explain with principle, the working of Ruby laser. 7M
10. a) Define acceptance angle and numerical aperture of an optical fiber. Derive an expression for numerical aperture of an optical fiber. 9M
b) An optical fiber has core and cladding refractive indices of 1.578 and 1.563 respectively. Calculate the numerical aperture and acceptance angle of an optical fiber. 6M
B. Tech I Semester Supplementary Examinations December – 2013 :
Regulations: VCE-R11
Engineering Physics :
(Common to Electrical and Electronics Engineering, Mechanical Engineering, Aeronautical Engineering & Civil Engineering)
Date : 21 December, 2013 Time : 3 Hours Max. Marks : 75
Answer ONE question from each Unit
All Questions Carry Equal Marks
All parts of the question must be answered in one place only
Unit – I :
1. a) Explain with suitable examples the ionic, covalent, metallic and Vander – Waal’s bonding in solids. 8M
b) Discuss structure of NaCl and calculate the spacing between Na+ and Cl- ions in it. Molecular weight of NaCl is 58.45 and its density is 2180 kgm-3. 7M
2. a) With lattice parameters draw the seven crystal systems. 7M
b) Write a short notes on bonding in crystals. 5M
c) Calculate atomic radii for the three types of cubic crystals in terms of the lattice constant. 3M
Unit – II :
3 a) Derive Bragg’s law of X-ray diffraction. Discuss powder method of crystal structure determination with figures. 10M
b) Explain Sol-gel method of synthesis of nano materials. 5M
4 a) Discuss the synthesis of nano materials by pulsed laser vapour deposition technique. Mention its advantages over other methods.8M
b) Define Miller indices and write the steps to find Miller indices. Draw the planes ?1 3 2? and (111) inside a unit cell.7M
Unit – III :
5 a) Set up one dimensional, time independence Schrodinger wave equation. Discuss the probability curves for ground and first excited states of a one dimensional potential well of infinite height and of width L m. 10M
b) Explain the properties of matter waves. Calculate the wavelength of radiation required to excite and electron from ground state to third excited state of an one dimensional potential well of infinite height and of width 4 nm. 5M
6 a) Discuss the origin of energy band formation based on Kronig-Penny model. 6M
b) Explain wave particle dualism. Discuss with neat diagrams, the G P Thompson experiment to establish de Broglie hypothesis. 10M
Unit – IV :
7. a) Define intensity of polarization and discuss any three types of polarization mechanisms ith pictorial representations.7M
b) Discuss hard and soft magnetic materials based on hysteresis curve and write any one application of each of them. 8M
8. a) Briefly explain the origin of magnetism and discuss the classification of magnetic materials based on their susceptibilities. 7M
b) Explain Meissner effect. 4M
c) The number of atoms in unit volume of hydrogen gas is 9.8 x 1026. Radius of hydrogen atom is 0.53 0 A . Calculate the polarizability and relative permittivity. 4M
Unit – V :
9. a) Explain induced absorption, spontaneous emission and stimulated emission with figures. 7M
b) Arrive at the conditions for laser action. 4M
c) Calculate numerical aperture and acceptance angle for an optical fiber of core RI = 1.53 and clad RI = 1.46. The fiber is kept in water of RI = 1.33. 4M
10. a) Define attenuation and write the equation for attenuation in an optical fiber. Discuss any three reasons for attenuation in an optical fiber. 8M
b) Calculate the temperature at which the ratio of populations of two energy levels separated by an energy 5 eV is 10-38. 3M
c) Explain graded index and step index fibers with refractive index profiles. 4M