Vinoba Bhave University 2008 B.Sc Physics Part -2 - Question Paper
Physics
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Total Pages8 VBPh(2)S/G (vii) Interference fringes can be obtained by: I a \ The division of wavefront only (b) The division of amplitude only (c) Either the division of wavefront or amplitude (d) Neither the division of wavefront or amplitude. (viii) Newtons ring are the fringes of: () Equal thickness () Equalinclination (c) Equal area ' (d) Equal intensity. (/a) The circular fringes produced in Michelsons interferometer are: [a) Curves of equal thickness (b) Curves of equal inclination (c) Identical with Newtons ring [d) Localised at one of the mirror. (x) KirchofTs law are applicable to: () D.C. only () A.C.only (e) A.C. and D.C. both id) None of the above. GROUPC Answer any four of tfie following 3. Discuss the growth and decay of current through L-R circuit. 10 4. Describe and explain the formulation of Newton's ring by reflected monochromatic light. Prove that in reflected light diameters of dark rings are proportional to the square roots-of the natural numbers. 10 5. Explain clearly what causes reverberation time in a hall and how it can be minimised. 10 6. Describe the construction and working of a Febry-Parot interferometer and deduce an expression for the intensity distribution of the fringes. 10 7. State and explain Kirchoff's law. Apply it to obtain the balance condition ofa Wheatstone bridge. 10 8. Obtain an expression for the power in an a.c. circuit contains L, C and R. What is power factor ? iO Answer from all the Groups as per direction The figures in the right-hand margin indicate marks Candidates arc required to give their answers in their own words as far as practicable GROUP-r-A (Compulsory) 1. Indicate correct answer in each of following-: the 1 x 10 (/') Intensity of sound depends upon: \a) Amplitude ib) Souare of amplitude (c) Inverse of amplitude (/>') Sonar is a technique: (a) Named after its inventor SONAR (b) Fitted m an aeroplane (c 1 Of sound navigation and ranging (d) Like radar fitted in motor cars of modem age. (iii \ Which of the following actions would be more effective in decreasing the reverberation time in an auditorium in which the audiance occupies wooden chairs ? (a) Requiring the audiance to rise from their seats (b) Opening the window (c) Opening the doors of the adjoing room. (iv) The speed of the transverse wave along a string depends upon: (a) Tension of the string () Length of the string (cl Density of the medium (d) Temperature of the medium. (v) To understand the flow of current in the network of conductors use is made of: [c) Joules law (</) Faradays law. I vi 1 Pitch of the sound depends: (a) Not upon frequency Upon frequency tc) Upon amplitude (j) upon density of the medium. |
9. Discuss the diffraction pattern produced by a circular aperture. What is its importance ? 10 10. Give the theory of concave reflection grating. Describe the various methods of mounting the same and point out their relative merits and demerits. 10 GROUPD 11. Answer any two questions of the following: 5 x () The intensity level of a sound is increased by 10 decibels. If the original intensity was 10'6watt/cm2. What is the new intensity? () A hall of volume 56,000 cubic ft. is found to have reverberation time 2 sec. If the area of sound absorbing surface be 7,000 sq.ft. Calculate the average absorption coefficient. (c) In the Newtons ring experiment the diameters of 5th and 15th rings were found to be 0-00336 m and 0-00 590 m respectively. If the radius of curvature of the planoconvex lens is 1 m. Calculate the wavelength of the light used. id) If the movable mirror of Michelson-interferometer is moved through a distance of 0-0589 mm, a shift of 200 fringes is observed. What is the wavelength of light ? |
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