Advanced Qualification · A-007 Feedlines and matching · A-007-009-004
For rectangular waveguide to transfer energy, the cross-section should be at least:
- A three-eighths wavelength
- B one-eighth wavelength
- C one-quarter wavelength
- D one-half wavelength
Correct answer: D — one-half wavelength. From the official ISED question bank, verified word for word.
Why
A rectangular waveguide acts like a hollow pipe for radio waves, and it cannot carry energy unless the pipe is wide enough to fit at least one-half wavelength of the signal inside. The full explanation — and one for every question — is in Pro.
Practise this section
Feedlines and matching at the advanced level: transmission line theory, impedance transformation, stubs and matching networks.