A) 1:2 B) 2:1 C) 1:1 D) 1:4
In frequency modulation the maximum frequency deviation is directly proportional to the product of modulation index (beta) and modulating frequency where beta is given by(Kp*Am)/fm. Now frequency deviation becomes (Kf *Am). So the frequency deviation depends on the magnitude of the modulating message signal.but not ntgr modulating signal frequency fm.Hence the deviation ratio is in the ratio 1:1