Electromagnetic Theory MCQ Questions Answers Electronics Engineering


11) In an air line, adjacent maxima are found at 12.5 cm and 37.5 cm. The operating frequency is

a) 1.5 GHz

b) 600 MHz

c) 300 MHz

d) 1.2 GHz

View Answer
Option – b)

12) The phenomenon of microwave signals following the curvature of earth is known as

a) Faraday effect

b) ducting

c) wave tilt

d) troposcatter

View Answer
Option – b)

13) Following antenna is frequently used for local area transmission at UHF/VHF

a) Ground monopole

b) Turnstile antenna

c) Slot antenna

d) Loop antenna

View Answer
Option – b)

14) In a line the VSWR of a load is 6dB. The reflection coefficient will be

a) 0.033

b) 0.33

c) 0.66

d) 3.3

View Answer
Option – b)

15) A waveguide operated below cut-off frequency can be used as

a) A phase shifter

b) An attenuator

c) An isolator

d) None of the above

View Answer
Option – b)

16) If the phase velocity of a plane wave in a perfect dielectric is 0.4 times its value in free space, then what is the relative permittivity of the dielectric ?

a) 6.25

b) 4.25

c) 2.5

d) 1.25

View Answer
Option – a)

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

a) Balun

b) Slotted line

c) Directional coupler

d) Quarter wave transformer

View Answer
Option – a)

18) The dominant mode in a circular waveguide is a

a) TEM mode

b) TM01 mode

c) TE21 mode

d) TE11 mode

View Answer
Option – d)

19) Equipotential surface about a point charge are in which one of the following forms ?

a) Spheres

b) Planes

c) Cylinders

d) Cubes

View Answer
Option – a)

20) Which one of the following modes has the highest cut-off wavelength in a rectangular waveguide ?

a) TE10

b) TE01

c) TM01

d) TM11

View Answer
Option – a)