Explain any two factors which justify the need of modulating a low frequency signal

(a) Explain any two factors which justify the need of modulating a low frequency signal.
(b) Write two advantages of frequency modulation over amplitude modulation

(a) (i) Effective power radiated by an antenna.
(ii) To avoid mixing up of signals from different transmitters.
(b) (i) FM signals can be demodulated even if the signal strength is weak.
(ii) FM reception is quite immune to noise as compared to AM reception.