If the range of a $TV$ telecast is to be doubled,the height of the transmitting antenna must be:

$A$ sinusoidal wave $y(t) = 40 \sin(10 \times 10^6 \pi t)$ is amplitude modulated by another sinusoidal wave $x(t) = 20 \sin(1000 \pi t)$. The amplitude of the minimum frequency component of the modulated signal is ...........

$A$ modulated signal $C_m(t)$ has the form $C_m(t) = 30 \sin(300\pi t) + 10 \cos(200\pi t) - 10 \cos(400\pi t)$. The carrier frequency $f_c$,the modulating frequency $f_m$,and the modulation index $\mu$ are respectively given by:

The waves used for line-of-sight $(LOS)$ communication are

An oscillator is producing $FM$ waves of frequency $2 \text{ kHz}$ with a frequency variation of $10 \text{ kHz}$. What is the modulation index?

If the amplitude of an audio signal is half the amplitude of the carrier wave,what is the modulation index?