M.Sc. (Semester (CBCS) Examination Mar/Apr-2018
Physics (Materials Science)
CONDENSED MATTER PHYSICS
Time: 2½ Hours
Max. Marks: 70
Instructions: Attempt five questions. Q.1 and Q.2 are compulsory. Attempt any three questions from Q. 3 to 7. Figures to the right indicate full marks. Use of non scientific calculator is allowed.
Q.1

Objectives questions:
06
Miller indices of crystal plane which intercepts at 3b, are




Bloch function is
φr k =ur k exp ik.r
φk r =ur k exp ik
φk r =uk r exp ik.r
φk r
p-type semiconductor is formed by adding impurity.
Bivalent
Trivalent
Tetravalent
Pentavalent
Induced electric dipole moment is directly proportional to
E
E2
E3
E1/2
Superconductor is below critical temperature.
Diamagnetic
Paramagnetic
Ferromagnetic
Antiferromagnetic
Coordination number of body centred cubic crystal structure is
6
8
10
12

State true or false.
08
Complex dielectric constant of non-polar solids does not depend on the complex polarisabilities. (True/False)
Superconductor has some flux density in presence of applied magnetic field.
Diamond is a conductor.
Crystalline solids are anisotropic.
A superconducting material has a critical temperature of 7.26 K at zero magnetic field and a critical field of 8×105 A/m at 0K. Then critical field at 5K is 4.2×105 A/m.
Relation between electronic polarisability and induced electric dipole moment is given by
Induced electric dipole moment is inversely proportional to electric field E.
NaCI shows orientation polarization.
Q.2
Write short notes:
14

Explain Type I and II superconductors.
05

Define Dielectric polarization. Give an expression for electronic polarizability.
05

Define
04
Cooper pair
Critical temperature
Critical current
Type I and II superconductor
Q.3

Define penetration depth. Give a relation between penetration depth and temperature.
08

Explain the concept of Brillouin zones.
06
Q.4

Explain the extended, reduced and periodic zone schemes. Plot energy as a function of wave vector for one dimensional lattice in above three zone schemes.
08

Explain electronic, ionic and orientational polarisabilities.
06
Q.5

What is meant by imperfections in crystals? Explain the various defects in the crystal.
08

Discuss the Meissner effect in detail.
06
Q.6

Obtain a solution of wave function of an electron in periodic potential.
08

Explain the extended, reduced and periodic zone schemes.
06
Q.7

Discuss the BCS theory in details.
08

Differentiate between polycrystalline, nanocrystalline and amorphous materials.
06