Basic Qualification · B-005 Basic electronics and theory · B-005-008-008
Un amplificateur linéaire augmente la puissance d'un émetteur de 5 watts à 50 watts. Le gain de puissance, exprimé en dB, sera de:
- A10 dB
- B30 dB
- C45 dB
- D20 dB
Correct answer: A — 10 dB. Question tirée de la banque officielle d'ISDE.
Why
Increasing power from 5 watts to 50 watts means the signal is ten times stronger, and in radio, every tenfold increase in power equals a gain of 10 decibels. The full explanation — and one for every question — is in Pro.
Practise this section
Basic electronics and theory is section B-005 of the Basic exam: The theory: Ohm's law, power, series and parallel circuits, AC and DC, frequency and wavelength, decibels, and the metric prefixes the exam leans on.
Drill B-005 — free, no account