Topic: Electromagnetics
Which of the following does not exist in waveguides
- A. TE waves
- B. TM waves
- C. TE waves and TM waves
- D. TEM waves
Answer: D. TEM waves
Explanation: Transverse Electromagnetic (TEM) waves require two separate conductors (an inner and an outer conductor, like in a coaxial cable) to propagate, as they need a return path for current at DC frequencies. A standard single-conductor hollow waveguide cannot support TEM waves.