The process of recovering the modulating signal from the modulated carrier wave is called:

We do not transmit low frequency signals to long distances because:
$(a)$ The size of the antenna should be comparable to signal wavelength,which is impractical for a signal of longer wavelength.
$(b)$ Effective power radiated by a long wavelength baseband signal would be high.
$(c)$ We want to avoid mixing up signals transmitted by different transmitters simultaneously.
$(d)$ Low frequency signals can be sent to long distances by superimposing them with a high frequency wave.
Therefore,the most suitable options are:

$A$ carrier wave of peak voltage $10 \,V$ is used to transmit a message signal. What should be the peak voltage of the modulating signal in order to have a modulation index of $80 \%$ (in $\,V$)?

The modulation index of an $FM$ carrier having a carrier swing of $200\, kHz$ and a modulating signal frequency of $10\, kHz$ is:

Which of the following modulated signals has the best noise tolerance?

$A$ speech signal of $3 kHz$ is used to modulate a carrier signal of frequency $1 MHz$,using amplitude modulation. The frequencies of the side bands will be