BSc Physics SEM I 2018 19 Dec 2018-19 PHYSICS PAPER I Question Paper - Mumbai University | munotes

Questions asked in this paper

• (2) Figures to the right indicate full marks

1. Q1 A) Select the correct alternative 12 marks
   • (1) Impulse is product of
   • (ii) | Poisson’s ratio is a ratio of
   • a. lateral strain and longitudinal b. Shear Stress and Shear
   • c. Volume Stress and Volume d. None of the above
   • (iii) Ifthe focal length of Huygen’s Eyepiece is 18cm then focal length of field lens is
   • a. 12cm b. 24cm
   • c. 36cm d.72cm
   • (iv) of light reflected at the boundary of a rarer to denser medium undergoes a phase change of degrees
   • (v) First law of thermodynamics is statement of.
   • a. Conservation of momentum b. Conservation of energy
   • c. Conservation of Angular d. Conservation of Mass
   • (vi) Change in internal energy in a thermodynamic process
   • a. Only on initial and final b. Upon path taken
   • c. Is always positive d. Is always negative
   • B) Answer in one sentence 3
   • (i) . What is turbulent flow? State the two types of the defects in a lens What is critical pressure?
   • C) Fill in the blanks 5
   • (i) In equation of continuity product of mass and velocity is (il) Along the axis of the pipe velocity of the fluid is
   • (iii) radius of the n th dark ring is directly proportional to the of the natural numbers in the reflected system
   • (iv) Asingle lens cannot form an image free from
   • (v) Isotherm is P-V diagram at constant
2. Q2 A) Attempt ANY ONE 8 marks
   • (i) Derive an expression for the moment of couple required to twist one end of the cylinder when other end is fixed for hollow
   • (ii) | Fora homogeneous isotropic material find the relation between young’s modulus Y bulk modulus K and Poisson’s ratio o
   • B) Attempt ANY ONE 8
   • (i) Poiseuille’s equation for liquid flowing in narrow tube State the assumptions made
   • (ii) | a) As an application of Bernoulli’s theorem, write a note on
   • b) On the basis of Bernoulli’s theorem, explain the upward lift to aero plane
   • C) Attempt ANY ONE 4
   • (i) Young’s modulus of a steel wire is 2.032x10! N/m? & its modulus of rigidity is 0.7x10!'N/m? find its Poisson’s ratio
   • (ii) In Atwood’s machine, passing over. frictionless, massless pulley has 10 kg block tied to one end and 12 kg block tied to the other. Find the acceleration and tension in the string
3. Q3 A) Attempt ANY ONE 8 marks
   • (i) Derive the expression for optical path difference between two rays in the case of interference due to reflected light in the thin
   • (ii) Describe Newton’s rings experiment and explain with necessary theory the formation of Newton’s rings
   • B) Attempt ANY ONE 8
   • (i) Derive an expression for the equivalent focal length for a system having two thin lenses separated by a finite distance
   • (ii) What is chromatic aberration? Derive the expression for the
   • C) Attempt ANY ONE 4
   • (i) In the wedge shaped film of refractive index 1.57, fringe spacing is Imm and wavelength of light used is Calculate the angle of wedge of film
   • (ii) Two convex lenses of focal lengths 10 cm and 20 cm are placed 5cm apart in air .Find the equivalent focal power of lens and its positions of principal points
4. Q4 A) Attempt ANY ONE 8 marks
   • (i). With the corrections to pressure and volume, arrive at Van der
   • (ii). Show that for adiabatic process, = constant A gas occupies 1000 cc of volume at 4 atm pressure. It expands adiabatically to 1190 cc and the resulting pressure is 3 atm
   • B) Attempt ANY ONE 8
   • (i) Show that for isothermal process work done, W is A perfect gas at room temperature having volume of 4m? and initial pressure of 2 atm undergoes isothermal expansion to a volume of 5 m? Calculate the work done by the gas
   • (ii) Show that for perfect
   • C) Attempt ANY ONE 4
   • (i) A quantity of air at and at atmospheric pressure is suddenly compressed to half of its original volume. Find the final temperature and pressure of the gas.(y = 1.4)
   • (ii) | An adiabatic container of volume V has an adiabatic partition making to compartments of volume V2. These two compartments have an ideal gas of moles and nzat temperatures T; and T2, pressure P; and P2. If the partition is removed, what are the equilibrium temperature and pressure of the composite system?
5. Q5 Attempt ANY FOUR 20 marks
   • (i) short note on stream line flow and turbulent flow
   • (ii) short note on limiting value of Poisson’s ratio
   • (iii) a short note on Ramsden’s eyepiece
   • (iv) . State the various methods of reducing spherical aberration State and explain zeroth law of thermodynamics
   • (vi) how the work done in a thermodynamic process is a

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