Amplitude modulation has

If a radio receiver amplifies all frequency signals equally and well,it is said to have high . . . . . . .

$A$ message signal of peak voltage $12 \ V$ is used to amplitude modulate a carrier signal of frequency $1.2 \ MHz$. The amplitude of the side bands is (in $V$)

$A$ basic communication system consists of:
$(a)$ Transmitter
$(b)$ Information source
$(c)$ User of information
$(d)$ Channel
$(e)$ Receiver
The correct sequence of the arrangement is:

For an amplitude modulated wave,the maximum and minimum amplitudes are $12 \,V$ and $3 \,V$ respectively. Then the modulation index is

The relationship between the maximum electron density $(N_{max})$ of the ionosphere and the critical frequency $(f_c)$ is given by: