In radio broadcasting,the transmission of sound waves is of the type.............

The radius of the Earth is $6400 \text{ km}$. If the height of the antenna is $500 \text{ m}$, then its range is: (in $\text{ km}$)

For efficient transmission of sound waves of wavelength $\lambda$,the minimum length of the antenna should be.....

The height of a transmitting antenna is $h \ m$ and the height of a receiving antenna is $45 \ m$. The distance between them is $40 \ km$. For satisfactory $Line\, of\, Sight$ $(LOS)$ communication between the two antennas,the height of the transmitting antenna $h$ must be ....... $m$. (Radius of the Earth $R = 6400 \ km$)

$A$ 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 $V$)

In the process of modulation,the audio waves are called ...........