3

20 Obtain Clausius-Mosctti formula.
21 Show that V.B=0. a
22 Give a brief account of comparison of Magneto statics and electrostatics

23 Use Biot-Savart law to find the magnetic field inside and outside an infinitely long cur:
carrying solenoid. a.

24 Explain magneto static boundary condition.

(5 x 4 = 20 ma
Answer any four questions, each question carries 4 marks :

25 An clectron with a velocity of 2.4 x 10% m/s flies into
135 Vm". It moves along a field line until it comes to a ha
by the electron within the field.

26 Three charges + 1.59 + 1.5¢ and - 39 are placed at the
side 6. Find the dipole moment of the charge distribution.

27 Dielectric constant of a gas at NTP is 1.000074. Calculate
gas when it is held in an external field of 3 x 104 Vm-!

28 A wire shaped to regular hexagon of side 2 cm. carries a €
magnetic induction at the centre of the hexagon.

29 Derive an expression for the gyro magnetic ratio.

electric field of inten:
ite the distance travel

equilateral triangk

at of each atom of t

2 amperes. Find t

30 In the Rowland ring 2.0 amp current is passing through th

unit length 10- turns /em. Magnetic Induction measured is 1
(b) M.

31 A toroidal winding of N turns surrounding a ferromag:

of width d has been cut. Calculate the value of mag:
material.

“number of turns
? Calculate

f which a narrow
the gap and in #]

: (4 > 4 = 16 mark
Answer any two questions, each question carries 10 marks :
32 Derive .an expression for the potential at a point due न au

33 Obtain Laptace’s equation in two and three dimensions.
State mean value and maximum value theorem,

nly charged spherical shel
1€ properties of the solution:

34 Explain the terms polarization and displacement. Derive
an expression for potential of polarized objects.

35 Discuss in detail the Ampere’s law in Magnetized materi als. | Derive an expression for th
magnetic field at any point inside and outside of a long copper rod of radius R carries -
uniformly distributed current I. :

relation connecting them. Deriv

٦

(2 x 10 = 20 marks