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

In a communication system,the process of superimposing a low-frequency signal on a high-frequency wave is known as:

An amplitude modulated wave is represented by $C_{m}(t)=10(1+0.2 \cos 12560 t) \sin (111 \times 10^{4} t)$ volts. The modulating frequency in $kHz$ will be ........... .

$A$ $TV$ 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 $m$)

The maximum distance up to which $TV$ transmission from a $TV$ tower of height $h$ can be received is proportional to

$A$ 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: