# CUSAT Previous Year Question Papers BE EE

# Electromagnetic Theory July 2009

# V Semester

**EC/EE/EI 501 Electromagnetic Theory**

**(2002 Scheme)**

I. a. Transform the given vector A = 3ax + 4ay + 5az in rectangular co-ordinate system to cylindrical co-ordinate system.

b. Obtain the expression for the capacitance of a pair of coaxial cylinders of radii ‘r,’and’r_{2}‘and length ‘V. The outer cylinder is earthed.

**OR**

III. a. Define electric field intensity. Derive expression for efectric field at any point due to ‘n^{1} point charges.

b. Verify the vector field A ~ yzax + zxay + xyaz is both irrotational and sotenoidal.

III. a. . State and explain Amperes circuital law and thus find the ‘H’ of a long solenoid.

b. An has a velocity of 10^{6m/}‘ in a_{x} direction in a magnetic field B=0 .2ax-0,3ay+0.5azwb/m^{2}, What is the E field present if no net force is being applied to the electron?

c. Compare electrical potential and scalar magnetic potential.

**OR**

IV. a. State and prove boundary conditions for E & H fields.

b. Show that the work done in moving a point charge from A to B is independent of the particular path selected to transport the charge.

V. a. State and express Maxwell’s equation in the integral and differential form.

b. Given, E = E_{m}Sin{wt -f3z)ayVjm in free space. Find B?

c. Explain the significance of skin depth.

**OR**

VI. a. Define a uniform plane wave and show that such a wave will not have field components in the direction of propagation.

b. Discuss the possibility of progressive plane wave with velocity equal to that of light.

VII. a. State and prove poynting theorem.

b. What is polarization? Explain types of polarization.

**OR**

VIII. a. Determine the transmission and reflection coefficient, when a plane wave falls normally on a dielectric medium.

b. Define Brewster angle and deduce its impression.

IX. a. Draw the equivalent circuit of a transmission line and explain its primary constants.

b. Discuss various impedance matching techniques employed in transmission line.

**OR**

X. a. Define VSWR and derive the relation between VSWR and reflection coefficient.

b. Why TEM mode doesn’t exist in wave guides?

c. A rectangular wave guide 5 cm x 2.5 cm, find

(i) cut-off frequency for the dominant mode

(ii) phase velocity and

(iii) group velocity if the operating frequency is 3.5 GHz.