Which of the following is the communication channel in case of radio communication?

If the maximum and minimum voltage of an $AM$ wave are $V_{max}$ and $V_{min}$,then the modulation index is given by:

$A$ 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 $V$)

The process of the loss of strength of a signal while propagating through a medium is known as:

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

$A$ signal of frequency $20 \, kHz$ and peak voltage $5 \, V$ is used to modulate a carrier wave of frequency $1.2 \, MHz$ and peak voltage $25 \, V$. Choose the correct statement.