MSc Physics (Electronics I) SEM III 2022 2023 Dec 2023 PHYSICS NUCLEAR PHYSICS Question Paper - Mumbai University | munotes

Questions asked in this paper

• (2) Figures to the right indicate full marks

1. Q1 (a) Attempt any one:
   • (i) State different methods used to determine nuclear size. Explain the method, 8 Coulomb energy difference between mirror nuclei to determine nuclear
   • (ii) Assuming the square well potential for deuteron, obtain the depth of potential 8 well for deuteron, if the width of potential well is 2.1 fm
   • (b) Attempt any one:
   • (i) State the expected and observed values of magnetic dipole moment and 4 electric quadrupole moment of deuteron. Which information is obtained for deuteron from small difference between measured and expected values of
   • (ii) Explain the properties: spin and parity of a nucleus. 4
2. Q2 (a) Attempt any one: Explain different modes of beta decay and obtain an expression for Q value of 8 each of these decay modes
   • (ii) Give an account of angular momentum and parity selection rules in gamma 8 decay. A nuclei decay from initial nuclear state with li = 3/2 to final nuclear state with Ip = 5/2. Obtain the allowed multipole gamma radiation emitted in the above decay
   • (b) Attempt any one:
   • (i) Fermi-Curie plot in Fermi theory of beta decay. State the importance 4 of this plot
   • (ii) Explain how Pauli neutrino hypothesis solved the anomalies in beta-ray 4
3. Q3 (a) Attempt any one:
   • (i) Define Q value of a nuclear reaction. Consider the endoergic reaction 8 X (x,y )Y, where the target is initially at rest. Show that the threshold energy for the endoergic reaction is Ey, = — and in the approximation
   • (ii) What is the fusion process? Explain the CNO cycle. 8
   • (b) Attempt any one:
   • (i) In the nuclear shell model, orbitals are filled in the order, 4
   • (a) What is responsible for the splitting between the states?
   • (b) Find the ground state angular momentum and parity for
   • (ii) If the average energy of 200 MeV is released in the fission of each how 4 much is used in one day in a reactor operating at a power of 50 MW?
4. Q4 (a) Attempt any one:
   • (i) the eightfold way representation of elementary particles. Draw and 8 explain the Baryons and Mesons Octets
   • (ii) Discuss the Weak Interaction process. Describe the characteristics of the same 8 with suitable example
   • (b) Attempt any one:
   • (i) charge conjugation operator and its features. 4
   • (ii) Draw the Feynman diagrams, in terms of transitions at quark level for 4 p* + as a purely hadronic weak interaction and by a strong
5. Q5 Attempt any
   • (a) Explain why deuteron cannot exist in an excited state 3
   • (b) Find the binding energy per nucleon for deuteron 3
   • (c) decay to by B- decay and itis 0 * to 1* transition. Identify whether it is 3 pure Fermi or pure Gamow-Teller or Fermi and Gamow-Teller transition in
   • (d) Explain why Ii = If = 0 transition is not allowed for gamma decay and when pure 3 multipole gamma transition is emitted in gamma decay
   • (e) A beam of neutrons is incident on a piece of gold. The intensity of the beam as a 3 function of depth t is given by = 1(0) exp(—o nt), o is the capture cross section and n is the number of target nuclei per unit volume. For t = 0.05 cm if the emerging intensity is 74 % of the original intensity, find the reaction cross section [ Given: density of Au32” = 19.32 x , Avogadro No.=6.023 x
   • (f) What are pick up and stripping reactions? Identify and state the type of following 3
   • (g) Write a note on strange particles. 3
   • (h) Explain muon decay process using Feynman diagrams. State the interaction 3 involved in the process

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