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?

Given the electric field of a complete amplitude modulated wave as $\vec E = \hat i E_c (1 + \frac{E_m}{E_c} \cos \omega_m t) \cos \omega_c t$,where the subscript $c$ stands for the carrier wave and $m$ for the modulating signal. The frequencies present in the modulated wave are:

$A$ $TV$ tower has a height of $100 \ m$. The average population density around the tower is $1000 \ \text{per} \ km^2$. The radius of the earth is $6.4 \times 10^6 \ m$. The population covered by the tower is:

In an amplitude modulated wave for an audio frequency of $500 \, \text{cycles/second}$, the appropriate carrier frequency will be ........ $\text{cycles/second}$.

If multiple waves with modulation indices $n_1, n_2, n_3, ...$ modulate a carrier wave,what is the total modulation index of the resulting wave?

In a modulation process where the pulse duration varies with the modulating signal,it is called ......