Advanced Qualification · A-005 Transmitters, modulation and processing · A-005-005-006
In an FM transmitter system, the amount of deviation from the centre frequency is determined solely by the:
- A amplitude and the frequency of the modulating frequency
- B modulating frequency and the amplitude of the centre frequency
- C amplitude of the modulating frequency
- D frequency of the modulating frequency
Correct answer: C — amplitude of the modulating frequency. From the official ISED question bank, verified word for word.
Why
In frequency modulation, the loudness or strength of your voice signal, known as the amplitude of the modulating frequency, directly controls how far the carrier wave swings away from its centre point. The full explanation — and one for every question — is in Pro.
Practise this section
Transmitters, modulation and processing: AM, FM, SSB, keying, speech processing, and the numbers behind occupied bandwidth.