Q. 2. (a) Describe briefly three factors which justify the
need for modulation of audio frequency signals
over long distances in communication. (b) Draw
the waveforms of (i) carrier wave, (ii) a modulating
signal and (iii) amplitude modulated wave.
Q. 3. (a) Give three reasons why modulation of a
message signal is necessary for long distance
transmission. (b) Show graphically an audio
signal, a carrier wave and an amplitude modulated
wave.
