Electromagnetic Theory and Transmission Lines Mid  II, April  2012
1.For normal incidence of the wave on perfect conductor

Surface current doesn’t exist

surface exists

conducting current exiasts

free charge exists on the surface

Answer: B
2.A standing wave

Progresses with less than light velocity

progresses with more than light velocity

progresses with equal to light velocity

does not progress

Answer: D
3.The range of reflection coefficient is

0 to 1

0 to infinity

1 to 1

1 to infinity

Answer: C
4.Electric and magnetic fields which are parallel

Constitute power flow

constitute infinite power flow

constitute unit magnitude power flow

no power flow

Answer: D
5.The propagation velocity of TE waves

Depends on frequency

independent of frequency

depends on square of frequency

varies inversely with frequency

Answer: A
6.As per the boundary condition,

The normal component of E is continuous across the boundary.

The tangential component of E is continuous across the boundary.

The tangential component of D is continuous across the boundary.

The normal component of H is continuous across the boundary

Answer: B
7.The magnetic field at the surface of a good conductor is 2A/m. The frequency of the field is 600 MHz. The surface r.m.s current density is

0.5 A/m

0.5 A/m2

2 A/m

2 A/m2

Answer: C
8.If the reflection coefficient is 1/2 then the swr is

Zero

one

1/3

3

Answer: D
9.The wave impedance over the cross section of wave guide

Increases with frequency

decreases with frequency

increases exponentially

constant

Answer: D
10.Hysteresis and eddy current losses in loading coils leads to

Increase in L

Decrease in L

Increase in R

decrease in R

Answer: C
11.The frequency at which the wave motion ceases is called __________.
Answer: Cutoff frequency.
12.A Lumped load line behaves as a _____.
Answer: Low pass filter.
13.By inserting inductance in series with the line to increase the inductance is called _______.
Answer: Loading.
14.One neper is = ___________.
Answer: 8.68 dB.
15.A short circuited λ/4 line can be used a __________.
Answer: Insulator.
16.The range of UHF is ___________ to _________.
Answer: 300 MHz to 3 GHz.
17.The loading practice is generally restricted to _______ only.
Answer: Cables.
18.When a transmission line is shorted, the first voltage minimum occurs at _________.
Answer: Load.
19.The center of smith chart represents ___________.
Answer: Matched load impedence.
20.Attenuation factor of TEM wave is proportional to ______ of frequency.
Answer: Square root.