JEE Main2015PhysicsCommunication SystemActual
A signal of 5 kHz frequency is amplitude modulated on a carrier wave of frequency 2 MHz . The frequencies of the resultant signal is/are:
Options
- A2000   kHz   and   1995   kHz
- B2   MHz   only
- C2005   kHz   and   1995   kHz
- D2005   kHz ,   2000   kHz   and   1995   kHz
Correct answer
D. 2005   kHz ,   2000   kHz   and   1995   kHz
Step-by-step solution
Frequency of signal wave = 5   kH z = f . Carrier wave frequency = 2 MHz = 2 0 0 0 kHz = f c . The resultant signal maximum frequency = f + f c = 5 + 2 0 0 0 kHz = 2 0 0 5 kHz Resultant signal minimum frequency = f c - f = 2 0 0 0 - 5 kHz = 1995 kHz