Electromagnetism MCQs

Question 1

A transmission line of length / < A./4 is open circuited at the far end. The input impedance is

Accepted Answer

capacitive

Answer

resistive

Answer

inductive

Answer

Z0/2

Question 2

A transmission line of length / < ?4 is at the far end. The input line is required to match over a wide frequency

Accepted Answer

inductive

Answer

resistive

Answer

capacitive

Answer

Z0/2

Question 3

A transmission with the load radiates energy

Accepted Answer

inside a hollow sphere.

Answer

in a well defined direction.

Answer

uniformally in all directions.

Answer

uniformally in horizontal plane.

Question 4

To couple a coaxial line to a parallel wire line, it is best to use

Accepted Answer

a balun

Answer

a slotted line

Answer

a directional coupler

Answer

a quarter wave line

Question 5

Radiation resistance of a halfwave dipole is

Accepted Answer

730

Answer

3770

Answer

300S2

Answer

500SI

Question 6

Main drawback of a two hole directional coupler is its

Accepted Answer

narrow bandwidth

Answer

poor directirity

Answer

poor directional coupling

Answer

high standing wave ratio

Question 7

Power gain GP of an antenna in a given direction is the ratio of

Accepted Answer

radiation intensity in that direction to the total input radiated power

Answer

radiation intensity in that direction to the average radiated power

Answer

average power to maximum power

Answer

peak power to rms power

Question 8

The effect of ground on radiation pattern of an antenna is

Accepted Answer

both and above

Answer

to produce more number of nulls.

Answer

to cause concellation of radiation along the ground

Answer

to change its effective wavelength

Question 9

Yagi antenna has

Accepted Answer

driven element, reflector element and several director elements

Answer

one driven element and one reflector element

Answer

one driven element and one director element

Answer

only a folded dipole