PHYSICS PAPER 2

Time Allowed: 3 Hours M=imumMarks: 300
Candidates should attempt Question 1 and 5 which are compulsory, and any three of the remammg questions selecttngat least one question from each &Jetton All questions carry equal marks

Answer any three of the folloWlng
The wave functi on 0f a particle is

Find the expectation values of position and momentum for the particle
A 200 eV merea,e 1n the energy of an electron changes its De Broglie wavelength by a factor
oftwo Calculate the milia! De Bra gli e wavelength 0f the electron

WhatlS the lowest non zero atlIH1ar momentum for an e1ementary' particle? Name alleast three e1ementary particles having such an angular momentum
Write the spectral symbol of the lenn wlth 5/2 and g 6/7

A sample 1S irradiated by a 5000 A radiation to gIVe a Raman line at 5050 5 A Calculate the Raman frequency
Explain, both red and VIolet degraded bands have been observed m electromc band systems but rotation-vibration spectra show bands degraded to red only
Treating CH mol ecule as an united atom, denve its resultant molecular e1 ectromc states
Calculate the moment of mertia of HCI molecule from the expressiOn VHCl= 20.68 whereJ=0,1,2,..

2. Solve the one dimensional Schro dinger wave equation with potential

Vex) Vo


DistingUish between a clasSical of zero pomt energy and a quantum mechan1cal harmomc osallator Explain the
Show that the motion ofa clasSical particle lS analogous to the motion of a wave packet, which can be constructed by sup erp 0Sl tion of a 1arge numb er 0f plane WeNes Construct such a WeNe packet and denve an expreSSiOn for its group velocity

3 Denve.an expresSion for the srm-orbit mteraction energy in one electro system Calculate the energy separahon between the levels Pl/2 and 2P3/3
Write the electronic configuration of mercury(Z 80) Obtain the spectral term for the normal and the first excited configuration of the atom
Denve an expressiOn for the electrical conductivity of metals on the baSls offree electron theory of metals

A diatom1c gas lS found to heNe a number of absorption bands in the ultraVloletreglon Each bandlS also observed to have a fine structure How can the observed spectrum be explamed and analyzed?
Explam the nature, ongm and Sigll1ficance 0 f 21 cm hydro gen line
Calculate the change 1n rotational constant(Ev)when deutenum lS substituted for hydrogen in hydrogen molecule 15

SEcnON B

5. Answer any three of the folloWlng
Explain why a neutral particle such as neutron possesses a limte value of magnetic moment, and how illS delenmned
Write down the e1ectrolllc configuration of
Be and "Mg in the ground slale of the nuclear shell model

(il Explam how neutrino was discovered from the -decay of radio active nuclei

Show that for a cubic lattice, the difference between the succeSSive I planes 1S given by
d



(il Discuss the vanation of free camer concentration with temperature for an mlnnSlC and extrinSic semiconductors


Explam the effect of negative and posilive voltage feedback on an amplifier characlenstics eCl


(il Show that a negative 1ogle OR gale is like a p oS! live 10 glC AND gale



DistinguiSh between Hadrons and Leptons

Which conservation laws are obeyed m nuclear reactions? Explam the Slglllficance ofQ value of a nuclear reaction

Explam shell model of the nucleus limitations of the shell model? Give eVIdence for nuclear shell structure What are the

Explam MeiSsner sup erconductivity effect and Josephson effect Descnbe the1f applications m the field of

DistingUish between particle and antiparticle. How antip arti c1 es were di scovered?

Mention the conservati on Iaws for strong, electromagneti and weak mteractions

What are the mam applications of JFET? Discuss their advantages over bipolar tranSiStors Explam the working of n-ch3lUlel JFET with the help of a schematic diagram

Write down the charactenstics of an ideal operational amplifier Explam the tenn virtual ground Draw a arcuit diagram showmg virtual ground manop erational amplifi er