# Calculation of frequency spectrum in AM wave

## Calculate the frequencies available in the frequency spectrum when a 2MHz carrier is modulated by two sinusoidal signals of 350Hz and 600Hz.

a.) 2000.35, 1999.65 and 2000.6, 1999.4

b.) 1999.35, 1999.65 and 2000.6, 2000.4

c.) 2000.35, 2000.65 and 2000.6, 2000.4

d.) 1999.35, 1999.65 and 1999.6, 1999.4

Correct Answer: a) 2000.35, 1999.65 and 2000.6, 1999.4

**Explanation: **

The frequencies obtained in the spectrum after the amplitude modulation are

f_{c}+f_{m} and f_{c}+f_{m}

therefore,

the available frequencies after modulation by 0.350 KHz are

2000KHz+ .350 KHz = 2000.35 and 2000KHz - 0.350 KHz = 1999.65

the available frequencies after modulation by 0.6 KHz are

2000KHz+0 .6 KHz = 2000.6 and 2000KHz - 0.6 KHz = 1999.4