Basic Qualification · B-006 Feedlines and antenna systems · B-006-008-011
Quelle est la longueur d'onde en espace libre ("free space") d'un signal de 2 MHz?
- A30 mètres
- B150 mètres
- C360 mètres
- D1 500 mètres
Correct answer: B — 150 mètres. Question tirée de la banque officielle d'ISDE.
Why
A 2 MHz signal has a wavelength of 150 metres because radio waves travel at roughly 300 million metres per second, and dividing this speed by the frequency of 2 million cycles per second gives 150. The full explanation — and one for every question — is in Pro.
Practise this section
Feedlines and antenna systems is section B-006 of the Basic exam: Getting the signal out: antennas, feedlines, SWR, baluns, matching, and why antenna length depends on frequency.
Drill B-006 — free, no account