Question

The given figure shows the frequency spectrum of an amplitude modulated wave.

1. What are the names of (ω_c – ω_m) and (ω_c + ω_m).

2. What is the value of amplitude of (ω_c – ω_m) if modulation is µ?

3. What is the modulation index of AM, if the voltage amplitude of the carrier wave is 2kV and side band voltage amplitude is 200V.

Answer 1

1. Lower side band frequency and upper side band frequency.

2. Value of the amplitude of the side band frequency is A_s = \(\frac{\mu A_c}{2}\) where A_c is amplitude of carrier.

3.  A_s = \(\frac{\mu A_c}{2},\mu=\frac{2A_s}{A_c}\) = \(\frac{2\times200}{2000}\) = 0.2