The range of frequency bands used for standard $AM$ broadcast is

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

For a television network,$5 \times 10^5$ channels are granted. If the central frequency of the microwave link is $25 \text{ GHz}$ and the allotted bandwidth for each channel is $2 \text{ kHz}$,then what percentage of the link is used for the network (in $\%$)?

$A$ carrier wave of peak voltage $15 \,V$ is used to transmit a message signal. If the modulation index is $60 \%$, then the peak voltage of the modulating signal is (in $\,V$)

In amplitude modulation,the amplitude of the carrier wave is $10 \ V$ and the amplitude of one of the sidebands is $2 \ V$. Then the modulation index is

$A$ carrier wave of peak voltage $20 V$ is used to transmit a message signal. For getting a modulation index of $60 \%$,the peak voltage of the modulating signal is (in $V$)