BSc Physics SEM III 2018 2019 2019 Physics III Question Paper - Mumbai University | munotes

Questions asked in this paper

• (2) Figures to the right indicate maximum marks

1. Q1 A) Select correct answer reverberation time for music is about seconds 12 marks
   • a) b)2to2.5 c)3to4 d) 4 to 5 2 The relations between probabilities of stimulated absorption and emission were given by Smaller distances result diffusion rates and larger distances result 4 ____ is the spontaneous net movement of solvent molecules through a selectively permeable membrane into a region of higher solute concentration, in the direction that tends to equalize the solute concentrations on the two sides The resistivity of metals increases with
   • a) Rise in temp b) Fall in temp c) Remains unchanged d)None 6 Smallest unit of energy Answer in one sentence (03) State Sabine’s formula
   • 2. Define pH
   • 3. Define polar dielectrics In graded index fibre the refractive index varies in the direction is the difference in electric potential between the interior and the exterior of a biological cell
   • 3. All organisms are constructed of and 4 Property of developing voltage when pressure is applied Property of inducing magnetic field opposite to the applied magnetic
2. Q2 A) Attempt any one State any eight applications of optical fibers 8 marks
   • 2. Explain fiber geometry and discuss the mechanism of transmission of
   • B) Attempt any one the following properties of laser: 8
   • (a) Coherence 2 Describe the construction and working of He-Ne laser
   • C) Attempt any one volume of a room is 600 m? The wall area of the room is 220 m?, the floor area is 120 and the ceiling area is 120 m*. The average sound absorption coefficient, (i) for the walls is 0.03; (ii) for the floor is 0.06 and (111) for the ceiling is 0.80. Calculate the average sound absorption coefficient and the reverberation time 2 Ahall has a volume of 2250 m? Its total absorption is equivalent to 100 of open window. What will be the effect on the reverberation time if audience fills the hall and thereby increase the absorption by another 100 4
3. Q3 A) Attempt any one What are biological fluids? Enlist them and give their properties 2 Explain patch-clamp technique, its principles and state its applications 8 marks
   • B) Attempt any one 1 Explain facilitated diffusion 2 What is action potential? Discuss types of action potential and explain characteristic of action potential 8
   • C) Attempt any one 1 Determine the resting potential across the cell membrane given that concentrations of K* (inside 400 mM, outside 10 mM) of Na* ( inside 50mM, outside 460 mM) and of Cl (inside 40 mM, outside 540mM) and the respective permiabilities of K*, Na* and Cl are 1, 0.03 and 0.1 4
   • 2. Explain the process of osmosis cell membrane. State its physical
4. Q4 A) Attempt any one 8 marks
   • 1. Mention any four important characteristics of alloys & any two Mention any four important characteristics of polymers & any two
   • B) Attempt any one Mention any four important characteristics of semiconducting materials & any two applications Mention any four important characteristics of insulating materials & any 8
   • C) Attempt any one QS. Attempt any Four (20) how reverberation affects the acoustics of a hall 2 Write a short note on : Sound distribution in an auditorium Hodgkin-Huxley model of action potential 5 Compare ferroelectric & dielectric materials and mention any one application of each 6 Define piezoelectric effect and mention any one application 4

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