University of Delhi 2010-2nd Year B.Sc PMCS (Physics, Mathematics, Computer Science) Prog Thermal Physics & Electromagnetism UNIVERSITY - Question Paper

[This question paper contains 3 printed pages ]

5223    Your Roll No

B Sc. Prog./II    J

MP-202 Thermal Physics & Electromagnetism (Admissions of 2005 and onwards)

Time 3 Hours    Maximum Marks 75

(Write your Roll No on the top immediately on receipt of this question paper)

Attempt any five questions All questions carry equal marks

1 (a) Define reversible and irreversible processes ⁹ Give examples of each    (3,3)

(b) StateZeroth and first law of thermodynamics Usinjfirst law of thermodynamics, show that for one ole of perfect gas

Cp - C = R

the symbols have their usual meaning

(2,2,5)

(a) Dfs euish between MaxweH-RoUzmanin, Fctrsu-

/ i -

fli/'ajand Bose-Einstein statistics    (6)

5223    2

(b) Using Fermi-Dirac distribution law, show that for a completely degenerate ideal fermi gas of N particles, the mean energy is given by

E = | N_f(0) where the symbols have their usual meaning

(9)

3    Using the Maxwells law of the distribution of velocities in an ideal gas, derive the expression for the following

(i) Average speed V (n) Root mean square V_ms

(in) Most probable speed V_m    (15)

l

4    (a) Show that Rayleigh-Jeans law andWeins law of

Black body radiation are special (|se of plancks law    (9)

(b) Obtain an expression for Ste n-Boltzmann constant

(6)

show that

5 State and explain Biot-Savart law a 0) V B = 0 Explain its significan (n) VxB = n₀J    (

\

i

where symbols have their usual neaiing 3,6,6)

6    (a) Find the force between two straight infinite parallel

wire carrying current Ij and I₂ separated by a distance d and placed in vacuum    (7)

(b) Using Gausss law find the electric field intensity between two infmite rectangular planes carrying surface charge densities a and ~<y respectively

(8)

7    Discuss the propagation of electromagnetic waves in dilute ionized plasma Obtain an expression for refractive index and plasma frequency    (8,7)

8    Write short notes on any two of the following

(a)    Law of equipartition of energy

(b)    Maxwells Modification of Amperes law

(c)    Thermodynamic potentials

(d)    Poyintings theorem    {IV2JV2)

Attachment: university-of-delhi-2010-b-sc-pmcs--physics--mathematics--computer-science--35218-1.pdf

Earning:   Approval pending.