Which of the following is the disadvantage of $FM$ over $AM$?

Which of the following is not a basic component of a communication system?

In a communication system,noise is most likely to affect the signal:

In the process of space communication,the use of a modem is necessary. In which one of the following modes does a modem act as a modulator and a demodulator respectively?

$A$ carrier signal $C(t)=25 \sin(2.512 \times 10^{10} t)$ is amplitude modulated by a message signal $m(t)=5 \sin(1.57 \times 10^{8} t)$ and transmitted through an antenna. What will be the bandwidth of the modulated signal?

The $...........$ is the link connecting the transmitter and the receiver.