Question

For efficient transmission, the characteristic impedance of the transmission line has to be

(a) 50 ohm

(b) 75 ohm

(c) Either 50 or 75 ohm

(d) Neither 50 nor 75 ohm

I have been asked this question during an interview.

Origin of the question is Waveguide Current and Excitation in portion Waveguides of Electromagnetic Theory

Answer 1

Correct answer is (c) Either 50 or 75 ohm

For explanation: Generally, for ideal transmission lines, the characteristic impedance should be either 50 ohm or 75 ohm.