Engineering Physics

Set No.1

Code No: RR10103

I B.Tech. Regular Examinations, June -2005 ENGINEERING PHYSICS ( Common to Civil Engineering, Mechanical Engineering, Chemical Engineering, Mechatronics, Metallurgy & Material Technology and Production Engineering) Time: 3 hours Max Marks: 80 Answer any FIVE Questions All Questions carry equal marks ????? 1. (a) Explain the colors in a thin film when exposed to sun light. (b) A soap film of refractive index 1.33 and thickness 5000 A.U. is exposed to white light. What wavelengths in the visible region are reflected. (c) Determine the refractive index of transparent liquid by using Newton’s ring method. 2. (a) What is meant by diffraction of light? Explain it on the basis of Huygen’s wave theory. (b) What are the types of diffraction and give the difference between them. (c) What is the difference between Interference and Diffraction? 3. (a) Explain the following: i. Polarization by selective absorption ii. Polarization by scattering. (b) Prove that if the angle of incidence corresponds to the Brewster’s angle, then the angle between reflected and refracted beams is 90o 4. (a) Describe the construction of a typical optical fiber and give the dimensions of the various parts. (b) Define the acceptance angle and numerical aperture. Obtain an expression for the numerical aperture of an optical fiber. (c) Calculate the numerical aperture and acceptance angle for an optical fiber with core and cladding refractive indices being 1.48 and 1.45 respectively. 5. (a) Define molar specific heat of a solid. (b) Give an account of the various theories of specific heat of a solid. Discuss any one of them in detail. 6. (a) Derive an expression for “loss tangent” of a dielectric medium. (b) How the dielectric materials are classified? 7. Write notes on the following: (a) Soft magnetic materials 1 of 2

Set No.1

Code No: RR10103 (b) Hard magnetic materials (c) Hysteresis curve. 8. (a) What is meant by structural materials?

(b) Why the material has to withstand high and low temperature for space application? (c) Discuss some of the materials used for space applications along with their properties. ?????

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Set No.2

Code No: RR10103

I B.Tech. Regular Examinations, June -2005 ENGINEERING PHYSICS ( Common to Civil Engineering, Mechanical Engineering, Chemical Engineering, Mechatronics, Metallurgy & Material Technology and Production Engineering) Time: 3 hours Max Marks: 80 Answer any FIVE Questions All Questions carry equal marks ????? 1. (a) What is superposition principle. (b) Explain the formation of Newton’s rings and obtain an expression to determine the wavelength of monochromatic light. (c) In a Newton’s rings experiment the diameter of 15th ring was found to be 0.59 cm and that of 5th ring was 0.336 cm. If the radius of curvature of lens is 100 cm find the wavelength of the light. 2. (a) Obtain the condition for primary and secondary maxima in Fraunhofer diffraction due to a single slit and derive an expression for width of the central maxima. (b) A lens of focal length 0.4 m and slit of width 0.2 mm are used to obtain diffraction pattern. Calculate the distance of first dark band and width of central maxima, if the wavelength of light used is 500 nm. 3. (a) What is meant by double refraction? (b) Explain briefly options axis and its characteristics. (c) Discuss the construction of a nicol prism. 4. (a) Describe the construction of a typical optical fiber and give the dimensions of the various parts. (b) Define the acceptance angle and numerical aperture. Obtain an expression for the numerical aperture of an optical fiber. (c) Calculate the numerical aperture and acceptance angle for an optical fiber with core and cladding refractive indices being 1.48 and 1.45 respectively. 5. (a) What is specific heat of a solid? Discuss its variation with temperature. (b) Obtain an expression for the lattice specific of a solid on the basis of Einstein’s model. 6. (a) How are the dielectric materials classified? (b) Write short notes on “Porcelain”. 7. (a) What are paramagnetic and diamagnetic materials? Give examples. (b) Discuss the temperature variation of susceptibilities in paramagnetic and diamagnetic materials. 1 of 2

Set No.2

Code No: RR10103

8. (a) Why are the airborne pressure vessels required in aerospace? (b) Explain the various properties of the materials used for airborne vessels along with their salient features. (c) Why is the magnesium alloy not used for the airborne vessels? ?????

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Set No.3

Code No: RR10103

I B.Tech. Regular Examinations, June -2005 ENGINEERING PHYSICS ( Common to Civil Engineering, Mechanical Engineering, Chemical Engineering, Mechatronics, Metallurgy & Material Technology and Production Engineering) Time: 3 hours Max Marks: 80 Answer any FIVE Questions All Questions carry equal marks ????? 1. (a) Describe the interference pattern obtained due to superposition of coherent sources. (b) Derive an expression for the distance between two successive bright fringes formed in Young’s experiment. (c) In a double slit experiment a light of λ= 5460 A.U. is exposed to slits which are 0.1 mm apart. The screen is placed 2 m away from the slits. What is the angular position of the 10th maximum and 1st minimum? 2. (a) What is meant by diffraction of light? Explain it on the basis of Huygen’s wave theory. (b) What are the types of diffraction and give the difference between them. (c) What is the difference between Interference and Diffraction? 3. (a) Explain the following terms in ultrasonics: i. ii. iii. iv.

Galton’s whistle Piezoelectric effect Acoustic impedance Attenuation.

(b) What is meant by non-destructive testing? Explain. (c) Discuss the important uses of ultrasonics. 4. (a) Explain the principle behind the functioning of an optical fibre. (b) Derive an expression for acceptance angle for an optical fibre. How it is related to numerical aperture? (c) An optical fibre has a numerical aperture of 0.20 and a cladding refractive index of 1.59. Find the acceptance angle for the fibre in water which has a refractive index of 1.33. 5. (a) Explain Thomson effect. (b) State and explain i. law of intermediate metals and ii. law of intermediate temperatures. 1 of 2

Set No.3

Code No: RR10103

(c) For a thermo-couple, the neutral temperature is 320◦ C. If the cold junction is at 200 C , calculate the temperature of inversion. 6. (a) How are the dielectric materials classified? (b) Write short notes on “Porcelain”. 7. (a) Explain the phenomenon of spontaneous magnetization in magnetic materials. (b) Discuss the characteristic features of ferromagnetic materials. 8. (a) Compare the relative merits of the various aircraft materials with suitable example. (b) Explain in brief the general system requirements for a spacecraft. ?????

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Set No.4

Code No: RR10103

I B.Tech. Regular Examinations, June -2005 ENGINEERING PHYSICS ( Common to Civil Engineering, Mechanical Engineering, Chemical Engineering, Mechatronics, Metallurgy & Material Technology and Production Engineering) Time: 3 hours Max Marks: 80 Answer any FIVE Questions All Questions carry equal marks ????? 1. (a) Explain how Newton’s rings are formed in the reflected light. (b) Derive the expressions for the diameters of dark and bright rings. (c) Newton’s rings are observed in the reflected light of wavelength 5900 A.U. The diameter of tenth dark ring is 0.5 cm. Find the radius of curvature of the lens used. 2. (a) What is meant by diffraction of light? Explain it on the basis of Huygen’s wave theory. (b) What are the types of diffraction and give the difference between them. (c) What is the difference between Interference and Diffraction? 3. (a) Define the following: i. Plane of vibration ii. Plane of polarization iii. Optic axis. (b) Differentiate the linearly polarized and circularly polarized lights. (c) Find the minimum thickness of half-wave and quarter-wave plates for a light beam (λ= 589.3nm) if µo = 1.65835 and µe = 1.48640. 4. (a) Explain the terms i. ii. iii. iv.

absorption, spontaneous emission stimulated emission population inversion, relating to laser.

(b) Describe the principle of lasing action. (c) Mention the important characteristics of laser beam. 5. (a) Discuss the variation of the specific heat of a solid with temperature. (b) What is Dulong and Petit’s law of specific heat of a solid? (c) Discuss the merits and demerits of Einstein’s theory of specific heat of solids. 6. (a) Explain, in detail, the terms dielectric loss and dielectric strength. 1 of 2

Set No.4

Code No: RR10103

(b) The relative permittivity of argon at NTP is 1.000435. Calculate the polarizability of the argon atom. 7. Write notes on the following: (a) Soft magnetic materials (b) Hard magnetic materials (c) Hysteresis curve. 8. (a) What is meant by hardness? (b) Explain the significance of hardness in materials. (c) What is meant by creep? (d) Explain the various factors which affect the creep. ?????

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