Physics B.Sc/BA UOG — University of Gujrat

UNIVERSITY OF GUJRAT

(B.A/B.Sc. Part-II)

Physics Paper-IV (Theory)

Attempt FIVE Questions in all. Section-A is Compulsory. Attempt TWO questions from Section-B and TWO from Section-C.

SECTION -A

1- Attempt any FOUR of the following:

a) Define LATTICE and UNIT CELL

b) What is QUANTIZATION OF ENERGY?

c) Why is SILICON (Si) often preferred to GERMANIUM (Ge) for making Semiconductor?

d) What is MASS DEFECT?

e) Define Q-VALUE of a Nuclear Reaction.

SECTION -B

2-

a) Explain the Conductor, Semiconductor and Insulator with the help of ENERGY BAND THEORY

b) Draw symbols for NOR and NOT Gate and explain their working.

3-

a) What is LINEAR OPERATOR and give Postulate of Quantum Mechanics?

b) Derive Time Independent Schrödinger Wave Equation.

4-

a) Define NUCLEAR FUSION and explain Nuclear Fission Reaction.

b) Explain NUCLEAR SPIN and MAGNETISM.

SECTION-C

5- A 300g body connected to a spring whose force constant 'k' is 3.0 N/m is oscillating with an amplitude 'A' of 10cm. Treat this system as a quantum oscillator and find:

a) The energy interval between adjacent energy levels.

b) The quantum number that describes the oscillation.

6- An electron is trapped in an infinitely deep well of width 'L'. If the electron is in ground state, what fraction of its time does it spend in the central third of well?

7- What is the approximate density of the nuclear matter from which all nuclei are made?

8- The isotopic ratio of 235U/238U in natural uranium deposits today is 0.0072.

What was this ratio 2.0x10^9 year ago? The half life of two isotopes are 0.704 x 10^9 year and 4.47 x 10^9 year respectively.