Basic Qualification · B-007 Radio wave propagation · B-007-002-002
What type of solar radiation is most responsible for ionization in the outer atmosphere?
- A Infrared
- B Ultraviolet
- C Microwave
- D Ionized particles
Correct answer: B — Ultraviolet. From the official ISED question bank, verified word for word.
Why
Ultraviolet radiation from the Sun carries enough energy to strip electrons from atoms in the upper atmosphere, creating the ionized layers that allow radio waves to bounce back to Earth. 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.