BSc Sem II 2014 2015 2015 Physcs Ll Question Paper - Mumbai University | munotes

Questions asked in this paper

1. Q1 Answer the following: 20 marks
   • A) Show how to measure the inductance of a coil using Maxwell’s Inductance bridge. What are its limitations? Also find the value of R, and L, for the given component values: Ry = 1000Q,
   • A) State Norton’s theorem. Illustrate it with suitable example. (8M)
   • B) What is Ballistic Galvanometer? Explain the differences between the Ballistic and the dead beat
   • B) State and explain Reciprocity theorem. (7M)
   • C) Explain De Sauty’s capacitance bridge. Find the condition for its balance Is the condition independent of frequency of the applied voltage? (5M)
   • C) Acoil of a suspended coil galvanometer has 500 turns, each of area 5 cm’, the radial magnetic field being 2090 oersted. A current of through the galvanometer produces a deflection of Determine the torque required to twist the suspension through | radian. (SM) ).2) Answer the following: (20 Marks )
   • A) Define: (i) Mass defect, (ii) Binding Energy, (iii) Binding fraction. Using the given data find the
   • B.E. of neutron in the nucleus. Express it in MeV and joules Given: = 7.016004, SLi = 6.015125 and = 1.008665. (8M)
   • A) Explain the law of successive disintegration. Derive an expression for the number of atoms in the first two daughter elements formed in the process. (8M)
   • B) Explain why an electron cannot exist inside the nucleus? (7M)
   • B) Define half-life time of radioactive element. Show that it is inversely proportional to the decay constant. What is half-life if the activity of a certain preparation of radioactive nuclei reduces
   • C) Define (i) Activity of Radioactive substance (ii) 1 Curie (5M)
   • C) Discuss in detail (i) Positron Emission and (ii) Electron capture. (5M)
2. Q3 Answer the following: ir production and also find threshold wavelength for pair production, (8M)
   • A) Write a note on pair produc OR
   • A) State and explain Heisenberg uncertainty princip
   • a) Position and Momentum Energy and Time i he de Broglie wavelength of baseball of mass 2.5kg, having velocity of 10 m/s, (8M,
   • B) Define group velocity and phase velocity and show that the phase velocity has no
   • C) Explain Compton Effect with neat and labelled diagram. Hence show that energy of photon which shows Compton effect is given by ") State and explain de Broglie’s hypothesis. (SN
   • E) Ifa photon has energy 1 KeV, what will be its wavelength and frequency? (SN
3. Q4 the following (Any 3) ; (15 Mark:
   • A) De Sauty’s Capacitance bridge has Ri = 800Q, R2= 12009 and Find the value of the other capacitor when the bridge is balanced. (SN
   • B) ABG has a Steady deflection of 150mm for a current of at a distance of | metre: It completes 10 oscillations in 62.8s. Find current and charge sensitivities, What should be the undamped throw when a charge of circulates through the BG? (SN
   • C) Determine (i) radius of a nucleus, (ij) Volume, (iii) Mass of nucleus and (iv) Density of a Copp
   • D) Calculate the half-life of a radioactive substance, if the activity of substance decreases to its original value in 60 days. 5)
   • E) Explain gravitational red shift
   • F) Derive the relationship between hase velocity (V p Velocity (Vp) and velocity (V,).

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