RGPV Question Papers
Electromagnetic Theory June 2005
Note: Attempt any five questions. All question carry equal marks.
1 (a) State Gauss law, use in to determine electric filed intensity due to a uniform surface charge
of infinite size.
(b) Given the electric filed, E=40xy ax +20x2ay + 2az V/m . Calculate VPQ ,given that P (1,-1,0) and
2 (a) In a charge free region of free space, a potential field is given as :
V(x,y0=5x3+ f(x) -2 y2.
(b) Drive an expression for energy density of stored energy in electric filed and from it find how
much energy is store in a parallel plate capacitor .
3 (a) Region z≤0 contains a perfect dielectric for which εr1 =2.5,while the region z> 0 is
by εr2= 4 . Let Et1 = -30 ax +50 ay +70 az V/m . Find :
(i) Et1 (ii) D2 (iii) P2 and (iv) θ2 .
(b) A conductor is placed in static electric field in air (i) What will be the electric field inside the
conductor, justify your answer . (ii) What will be the electric field at the interface of air and
conductor ? (iii) Will there be any charge on conductor surface, if yes, will it be more at round
edge or sharp edge ? Justify your answer .
4 (a) Define curl of a vector field and an expression for curl of magnetic filed H.
(b) A distribution line consists of straight parallel conductors supported on the cross arms of
wooden poles space 100m apart . The normal spacing between the two conductor is 20 cm. A
current of 10000 A flows down one conductor and back the other during a fault . Drive an
expression for force between the conductor and calculate the same .
5 (a) Define magnetic dipole moment magnetization vector and establish a relation between filed
magnetic filed intensity , magnetic flux density and magnetization vector.
(b) Write a short note on vector magnetic potential.
6 (a) A straight conductor of 0.2 m lies on the x-axis with one end of origin. The conductor is subjected
to a magnetic flux density B= 0.04 ay T and velocity v= 2.5 sin 1000 az m/s . Calculate the motional
electric field intensity and e.m.f. induced in the conductor .
(b) Write Maxwell’s equations in point from for time varying fields and explain the meaning behind
© Calculate the self –induction and the mutual inductances between two coaxial solenoids of radius 2
cm and 3 cm with turns /m 50 and 80 respectively .
7 (a) Explain phenomenon of wave propagation in dielectric medium for sinusoid ally time varying
uniform plan wave . Discuss attenuation coefficient , complex permittivity ,loss tangent , phase
constant, phase velocity ,wavelength and characteristic impedance .
(b) A uniform plan wave in free space is given by Ēs =200 e –j.01z-ax V/m . Find the instantaneous value
of pointing vector at (i) t=0, z =15 and 45m (ii) z=0, t = 40 and 120 ns.
8 (a) Determine the amplitudes of reflected and transmitted E and H fields at the interface between
two regions . The characteristics of region are εr1=8,µr1 =1 and σ1= 0, region 2 is free space . The
incident E+0 in region is 1 is of 1.5 V/m . Assume normal incidence . Also find the average power in
two regions .
(b) Define surface impedance as referred to the electric over a conductor surface drive an expression
for it . For a perfect conductor, relate it to skin a depth.