Basic Qualification · B-007 Radio wave propagation · B-007-008-003
What type of VHF/UHF propagation depends upon small variations in density and water-vapour content?
- A Tropospheric ducting
- B Ionospheric scatter
- C Sporadic-E
- D Tropospheric scatter
Correct answer: D — Tropospheric scatter. From the official ISED question bank, verified word for word.
Why
Tropospheric scatter happens when VHF and UHF signals bounce off tiny, random changes in air density and water vapour within the lower atmosphere, letting you reach stations beyond the normal horizon. The full explanation — and one for every question — is in Pro.
Practise this section
How signals travel: the ionosphere and its layers, skip, ground wave, sporadic E, and which bands work when.