What does an FM signal sound like when received slightly off frequency?
The audio increases in pitch
The audio decrease in pitch
There is no effect except for reduction in amplitude
The audio becomes distorted✓Bonne réponse
Explication
An FM detector converts frequency deviation to audio only over a limited linear range centred on the tuned frequency. If the signal sits off centre, part of the deviation falls outside that range and the recovered audio comes out distorted rather than merely quieter or shifted in pitch.