The maximum amplitude of an $AM$ wave is $90 \ V$ and the minimum amplitude is $10 \ V$. What is the modulation index of the $AM$ wave in percentage?

Carrier waves are used for communicating signals over long distances because:

What is the frequency range of signals that can be transmitted using a $Twisted\, pair\, wire$?

The wavelength of the carrier waves in a modern optical fiber communication network is close to ........ $nm$.

The height of a transmission antenna is $100 \, m$. The population density is $1000 \, \text{people}/km^2$. How many people can watch the program?

$A$ 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