$AM$ (Amplitude Modulation) is used for broadcasting because...

$A$ 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 $V$)

This question has Statement-$1$ and Statement-$2$. Of the four choices given after the statements, choose the one that best describes the two statements.
Statement-$1$: Sky wave signals are used for long-distance radio communication. These signals are, in general, less stable than ground wave signals.
Statement-$2$: The state of the ionosphere varies from hour to hour, day to day, and season to season.

$List-I$	$List-II$
$A.$ Facsimile	$I.$ Static Document Image
$B.$ Guided media Channel	$II.$ Local Broadcast Radio
$C.$ Frequency Modulation	$III.$ Rectangular wave
$D.$ Digital Signal	$IV.$ Optical Fiber

Choose the correct answer from the following options:

$A$ message signal of $12 kHz$ and peak voltage $20 V$ is used to modulate a carrier wave of frequency $12 MHz$ and peak voltage $30 V$. Then,the modulation index is

The figure shows the waveform of an amplitude modulated wave. Its modulation factor is