Basic Qualification · B-006 Feedlines and antenna systems · B-006-008-004
The velocity of propagation of radio frequency energy in free space is:
- A 300 000 kilometres per second
- B 200 000 kilometres per second
- C 150 000 kilometres per second
- D 186 000 kilometres per second
Correct answer: A — 300 000 kilometres per second. From the official ISED question bank, verified word for word.
Why
Radio waves travel through empty space at the speed of light, which is exactly 300 000 kilometres per second. The full explanation — and one for every question — is in Pro.
Practise this section
Getting the signal out: antennas, feedlines, SWR, baluns, matching, and why antenna length depends on frequency.