# Electromagnetic Theory Questions and Answers – Transverse Electric Magnetic Waves(TEM)

This set of Electromagnetic Theory Multiple Choice Questions & Answers (MCQs) focuses on “Transverse Electric Magnetic Waves”.

1. In a transverse electric magnetic wave, which of the following will be true?
a) E is transverse to H
b) E is transverse to wave direction
c) H is transverse to wave direction
d) E and H are transverse to wave direction

Explanation: In the transverse electric magnetic wave (TEM wave), both the electric and magnetic field strengths are transverse to the wave propagation.

2. The cut off frequency of the TEM wave is
a) 0
b) 1 GHz
c) 6 GHz
d) infinity

Explanation: The TEM waves have both E and H perpendicular to the guide axis. Thus its cut off frequency is zero.

3. Which component is non zero in a TEM wave?
a) Ex
b) Hz
c) Ez
d) Attenuation constant

Explanation: In a TEM wave, the wave propagates along the guided axis. Thus the components Ez and Hz are zero. The attenuation is also zero. The non-zero component will be Ex.

4. TEM wave can propagate in rectangular waveguides. State true/false.
a) True
b) False

Explanation: The rectangular waveguide does not allow the TEM wave. TEM mode can exist only in two conductor system and not in hollow waveguide in which the centre conductor does not exist.

5. The cut off wavelength in the TEM wave will be
a) 0
b) Negative
c) Infinity
d) 1/6 GHz

Explanation: The cut off frequency in a TEM wave is zero. Thus the cut off wavelength will be infinity.

6. The guided wavelength of a TEM wave in a waveguide having a wavelength of 5 units is
a) 0
b) Infinity
c) 5
d) 1/5

Explanation: The guided wavelength is same as the wavelength of the waveguide with a TEM wave. Thus the guided wavelength is 5 units.

7. The guided phase constant of a TEM wave in a waveguide with a phase constant of 2.8 units is
a) 2.8
b) 1.4
c) 0
d) Infinity

Explanation: The guided phase constant is same as the phase constant of the waveguide. For the given data, the guided phase constant is 2.8 units.

8. Which type of transmission line accepts the TEM wave?
a) Copper cables
b) Coaxial cable
c) Rectangular waveguides
d) Circular waveguides

Explanation: Hollow transmission lines support TE and TM waves only. The TEM wave is possible only in the coaxial cable transmission line, which is not hollow.

9. For a TEM wave to propagate in a medium, the medium has to be
a) Air
b) Insulator
c) Dispersive
d) Non dispersive

Explanation: The medium in which the TEM waves propagate has to be non- dispersive. This implies the phase velocity and the characteristic impedance has to be constant over a wide band.

10. Stripline and parallel plate waveguides support the TEM wave. State true/false.
a) True
b) False

Explanation: The stripline and parallel plate waveguides are not hollow and the dielectric is lossless. The medium is non dispersive. Thus the statement is true.

Sanfoundry Global Education & Learning Series – Electromagnetic Theory.
To practice all areas of Electromagnetic Theory, here is complete set of 1000+ Multiple Choice Questions and Answers.

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