What is the frequency of an $FM$ transmitter without a signal input?

The sound produced by a tuning fork is a/an .....

$A$ signal of $20 kHz$ is being carried on a carrier wave of $3 MHz$. What are the side-band frequencies?

In a communication system,a repeater is used to extend the range of transmission. It is a combination of:

An amplitude modulated signal is plotted below. Which one of the following best describes the above signal?

$A$ person tries to broadcast with the same antenna both the signals at $10^7 \,Hz$ and $10^6 \,Hz$. If the receiver at some distance has to receive an equal strength for both the frequencies, then the broadcaster has to approximately increase the signal strength at $10^6 \,Hz$ to $10^7 \,Hz$ by