For an amplitude-modulated wave,the maximum amplitude is $9 \ V$ and the minimum amplitude is $3 \ V$. The modulation index is ........$\%$.

For a television network,$5 \times 10^5$ channels are granted. If the central frequency of the microwave link is $25 \text{ GHz}$ and the allotted bandwidth for each channel is $2 \text{ kHz}$,then what percentage of the link is used for the network (in $\%$)?

$A$ $TV$ transmitter has a range of $50 \ km$. The height of the $TV$ transmitter is $......$ (Radius of the earth $R_e = 6.4 \times 10^6 \ m$) (in $m$)

What is an antenna?

If the maximum and minimum amplitudes of a modulated wave are $25 \ V$ and $5 \ V$ respectively,then the modulation index is

For an $FM$ carrier with a carrier frequency of $200 \text{ kHz}$ and a modulating frequency of $10 \text{ kHz}$,the modulation index is...