PHYSICS
Paper-II
Time Allowed Three Hours
Maximum Marks 200

Question Paper Specific Instructions

Please read each of the following instructions carefully before attempting
questions:

There are EIGHT questions in all, Out of which FIVE are to be attempted.
Questions no. 1 and 5 are compulsory.-Out of the remaining SIX. questions, THREE are to
be attempted ..electing at least ONE question from each of the Sections A a..d B.
·

Attempts of questions shall be counted in sequential order. Unless strzi<;k off,· attempt of a
question shall be counted .even if attempted partly. Any page or portion·of the ·page left
blank in the Question-cum-Answer Booklet must be clearly struck off..

All questions carry equal marks. The number. of marks carried by a question/ part is
indicated against it.


Answers must be written in ENGUSH only.


Otherworldliness mentioned, symbols and TJ,Notations have their usual standard meanings.
Assume suitable data, if necessary, and indicate the same clearly.
Neat sketches may be the,drawn, wherever required.

List of Useful Constants .

Mass of proton 1 ·673 X 10-27 kg
Mass of neutron =·1·675 X 10-27 kg
mass of electron =-9.11 X 10-3l kg
Plan ck constant 6·626 X 10-34 Js
Boltzmann constant 1·380 X 10-23 J}rl
Bohr magneton 9.•273 x 10-24 A m.2
Nuclear magneton 5·051 x 10-27 J'r1 m2)
Electronic charge 1·602 X 10-19·C
Atomic mass also ·x io-27 kg=931MeV
g.. 5·5855 flN. 1 ·00721 u
1·00866 ..He) 4·00..603 u
·= 12·00000 u :..Sr) 86·908893 u
2·014022 .. iH) .. 3·0160500 ..


SECTION A
Ql. Answer all of the following questions 8x5=40

Give an account of Heisenberg's Uncertainty principle. Outline an idealised experiment to bring out its significance.
Find the de Broglie wavelength of a neutron moving with a kinetic energy of 500 eV. eV 1·602 x 10-19
Determine the values of the total angular momentum for 3d electron.
Use Hund's rules to find the ground-state quantum numbers, Land S of Carbon and Oxygen atoms.
Calculate the strength of the magnetic field to bring a proton nucleus and a 13C nucleus to resonate at this frequency. Magnetic· moment of proton 2·7927 µN and magnetic moment of 13C =0·7022 µN. The NMR instrument operates at 30·256 MHz.

Q2. (a)Deduce the commutation relations between the components of angular. momentum operator L

[Lx,Ly]=ihLx
[LY,LZ]=ihLx
[Lx,Ly]=ihLy
using the commutation relations
Pxl Pyl Pzl ih 20

Solve the Schrodinger equation for an electron of mass m confined in a one-dimensional potential well 0f the form
V when O x L
infinity, when x x

Obtain the discrete energy levels and the normalized eigenfunctions. 10+5+5=20

Q3. State the postulates of Bohr regarding his atom model.Obtain the expressions for the radius and electron-energy of the nth orbit. Explain how Bohr's atom model successfully accounts for the hydrogen spectrum. 5+10+5=20
Explain Russel Saunders coupling. Discuss the summation rules for orbital angular momentum, spin angular momentum and total angular momentum quantum numbers. 5+5=10
What is 'multiplicity' Give the term symbol for the following
cases:
1/2 L=2
S=1 L=l

Q4. Distinguish between fluorescence and phosphorescence in electronically excited molecules. 10
Calculate the most probable value of for an electron in the ground state of the hydrogen atom. 10
Derive the rotational-vibrational energy levels of a diatomic molecule. Give the analysis of spectral lines. 15+5=20 ·


SECTION B

Q5. Answer all of the following questions 8x5=40

Discuss the four basic types of fundamental interactions in nature and compare them.
(b)What is kinematics of nuclear reaction What is the Q-value and its significance
Compute the density of a typical nucleus and find the resultant mass, if we could manufacture a nucleus with a radius of 1 cm. 8
What are called intrinsic and extrinsic semiconductors
Construct the following function with logic gates Y D G H

Q6. Explain the term critical magnetic field in a superconductor. How does the critical magnetic field vary with temperature in Type-I and Type-II superconductors Whatever is Meissner effect 5+10+5=20

Discuss the shell model of the nucleus. What are its merits 15+5=20

7 With a suitable circuit diagram and theory explain the use of OP-Amps as Adder, and Integrator. 20

(b)Describe the quark model. Obta1n the quark composition of baryons and mesons. 10+5+5=20

QB. Obtain the ground-state wave function, depth of potential and rarige of nuclear force in deuteron and discuss. Also prove that no bound state exists for

Explain the operation of NOR gate with a logical diagram and truth
table. Show how NOR gate can be used as Universal gate. 5+5+10=20