Coaxial cable,a widely used wire medium,offers an approximate frequency bandwidth of:

$A$ 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 $V$)

Which of the following devices is not a transducer?

The physical sizes of the transmitter and receiver antenna in a communication system are

The modulation index of an $FM$ carrier having a carrier swing of $200\, kHz$ and a modulating signal frequency of $10\, kHz$ is:

The $T.V.$ transmission tower in Delhi has a height of $245 \ m$. The distance up to which the broadcast can be received (taking the radius of the earth to be $6.4 \times 10^6 \ m$) is .......... $km$.