Communication Systems - Engineering

Q1:

A 1000 kHz carrier is simultaneously modulated with 300 Hz, 800 Hz and 2 kHz audio sine waves. The frequencies present in the output will be

A 998 kHz and 1002 kHz

B 998 kHz, 999.2 kHz, 1000.8 kHz, 1002.0 kHz

C 998 kHz, 999.2 kHz, 999.7 kHz, 1000.3 kHz, 1000.8 kHz and 1000.2 kHz

D none of the above

ANS:C - 998 kHz, 999.2 kHz, 999.7 kHz, 1000.3 kHz, 1000.8 kHz and 1000.2 kHz

Answer should be B. In C it should be 1002 rather than 1000.2 kHz.