Multiple choice

Which of the following statements is true regarding the fundamental mode of the metallic waveguides shown?

  1. Only P has no cutoff-frequency

  2. Only Q has no cutoff-frequency

  3. Only R has no cutoff-frequency

  4. All three have cutoff-frequencies

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Rectangular and cylindrical waveguide doesn't support TEM modes and have cut off frequency.

Coaxial cable support TEM wave and doesn't have cut off frequency