Anna University Chennai 2005 B.E Electrical and Electronics Engineering ELECTROMAGNETIC THEORY for - Question Paper

B.E./B.Tech. DEGREE exam
Third Semester
Electrical and Electronics Engineering
EE 231 — ELECTROMAGNETIC THEORY
Time : 3 hours Maximum : 100 marks
ans ALL ques..
PART A — (10 ? two = 20 marks)
1. Under what conditions will the field intensity be solenoidal and irrotational?
2. State Gauss's legal regulations. Under what condition is Gauss's legal regulations especially useful in
determining the E–field intensity of a charge distribution?
3. A fixed voltage is applied across a parallel plate capacitor. Does electric flux
density depend on the ? of the medium? discuss.
4. Can a static magnetic field exist in a good conductor? discuss.
5. Compare the usefulness of Ampere's circuital legal regulations and Biot–Savart legal regulations in
determining B
?
of a current carrying circuit.
6. discuss the significance of displacement current and eddy current.
7. Why is the H–field immediately outside of a perfect conductor tangential to the
conductor surface?
8. describe Poynting vector. What is the SI unit for this vector?
9. elaborate the boundary conditions of electro magnetic wave at the interface
ranging from 2 loss less dielectric media?
D 034
2 D 034
10. discuss the method of images to obtain field at a point due to a point charge.
PART B — (5 ? 16 = 80 marks)
11. (i) describe Lenz's legal regulations with mathematical expression. (4)
(ii) obtain the magnetic field intensity at a distance x above an infinite
straight wire carrying a steady current I. (12)
12. (a) obtain the potential of a uniformly charged spherical shell of radius R at
points inside and outside. (16)
Or
(b) (i) provided the potential 2
10 sin cos
r
V
? ?
? obtain the electric flux density
D at , 0)
2
(2,
?
. (10)
(ii) compute the work done in moving a 10 ? C charge from point
A (1, 30?, 120?) to B (4, 90?, 60?). Use spherical (r, ? , ? ) co–ordinate
system. (6)
13. (a) 2 electrodes at potentials 0 V ? V and V ? 0 volt are separated by a
distance d along z–axis. The region ranging from the electrodes contains a
uniform charge density 0 ? , which is generated by electrode at 0 V and
collected at electrode at 0 V. compute the electric field at any point Z.
What is the direction of the field? (16)
Or
(b) Derive Maxwell's curl equations from Ampere's legal regulations and Faraday's legal regulations.
Express the equations in phasor form for time harmonic fields. (16)
14. (a) discuss the Finite Difference Method to obtain potential at a point in a
charge free medium. (16)
Or
(b) 2 infinite parallel plates separated by a distance d are perpendicular
to x–axis. The plate at x ? 0 is at potential 0 V and that at x ? d is at
potential 0 V ? V . obtain the E–field and potential variation ranging from the
3 D 034
plates by separation of variable method. Plot these parameters versus x.
(16)
15. (a) provide a mathematical representation of plane waves propagating in +Z
direction in an infinite loss less dielectric medium. discuss how this
medium is characterised by propagation constant and wave impedance.
(16)
Or
(b) A linearly polarised plane wave E ? 10 e? j k, r ?mV m? propagates through
free space at an angle ? with respect to Z–axis. compute the avg.
power flow through one m2 surface of circular shape lying on
xy plane with center at the origin. Under what condition power flow will
be maximum? (16)
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Earning:   Approval pending.