The process of increasing the strength of a signal using an electronic circuit is called

An antenna of length $3 \ m$ will effectively radiate which frequency?

If the height of the transmitting tower is increased by $30 \%$,then the area covered by it increases by (in $\%$)

An antenna behaves as a resonant circuit only when its length is

$A$ $500\, Hz$ modulating voltage fed into an $FM$ generator produces a frequency deviation of $2.25\, kHz$. If the amplitude of the voltage is kept constant but the frequency is raised to $6\, kHz$,then the new frequency deviation will be.......$kHz$.

Consider an optical communication system operating at a wavelength of $\lambda \sim 800 \, nm$. If only $1\%$ of the optical source frequency is available for optical communication,how many channels can be accommodated for a bandwidth of $8 \, kHz$?