Q18 of 26 Page 1

(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.


Two factor which shows why we need to modulate low frequency signal.


1. The size of the antenna or the dish is the basic requirement of sending and receiving signal, the size of the antenna can change the wavelength of the signal or vice versa meaning high wavelength need large antenna.


2. High energy due to high frequency signals are carried over a long distance even after energy loss due to attenuation.


The advantage of frequency modulation over amplitude modulation is:


1. The FM or frequency modulation is far better than the AM or amplitude modulation because FM is far more stable than AM over large distances and requires low power.


2. The background noise in AM is larger than the FM causing limitation to the AM receiving devices listening.


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