$A$ $T$.$V$. tower has a height of $100 \, m$. The average population density around the tower is $1000 \, km^{-2}$ and the radius of the earth is $6.37 \times 10^6 \, m$. The population covered is

The maximum amplitude of an $AM$ wave is $90 \ V$ and the minimum amplitude is $10 \ V$. What is the amplitude of the modulating wave in the given $AM$ wave (in $V$)?

$A$ sinusoidal carrier voltage is amplitude modulated. The resultant amplitude modulated wave has maximum and minimum amplitude of $120 \, V$ and $80 \, V$ respectively. The amplitude of each sideband is $.......... \, V$.

$A$ carrier wave $v_{c}(t) = 160 \sin(2 \pi \times 10^{6} t) \text{ V}$ is made to vary between $V_{\max} = 200 \text{ V}$ and $V_{\min} = 120 \text{ V}$ by a message signal $v_{m}(t) = A_{m} \sin(2 \pi \times 10^{3} t) \text{ V}$. The peak voltage $A_{m}$ of the modulating signal is ..... .

In a communication system,the range for line-of-sight propagation on Earth is $d$ for an antenna height of $h$. If $h$ is doubled,then the new range is:

$A$ signal $A \cos \omega t$ is transmitted using $v_0 \sin \omega_0 t$ as a carrier wave. The correct amplitude modulated $(AM)$ signal is: