Digital signal

While tuning in a certain broadcast station with a receiver,we are actually

$A$ $TV$ transmission tower of height $h$ covers a range of distance $d$. By how much will the range change if the height is increased to $3/2 h$?

If $E_c$ and $E_m$ are peak values of carrier and modulating signals,respectively,then for $100 \%$ modulation,

The advantage of an optical fibre is:

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