Broadcasting antennas are generally

Frequencies in the $UHF$ range normally propagate by means of:

An $AM$ wave has $1800 \,W$ of total power content. For $100 \%$ modulation, the carrier should have power content equal to: (in $\,W$)

In an $AM$ detector circuit,$R = 2 \text{ k}\Omega$ and $C = 1 \mu\text{F}$. This circuit will demodulate a carrier frequency of ......... $\text{kHz}$ effectively.

If the range of a $TV$ telecast is to be doubled,the height of the transmitting antenna must be:

The digital signals are used for transmission in communication systems. They are