$A$ message signal of frequency $10 kHz$ and peak voltage of $15 V$ is used to modulate a carrier frequency of $1 MHz$ and peak voltage of $30 V$. Determine the modulation index.

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

If the amplitude of the modulated wave and the amplitude of the signal are equal, then the modulation index is .....$\%$

$A$ transmitting antenna at the top of a tower has height $32\, m$ and the height of the receiving antenna is $50\, m$. What is the maximum distance between them for satisfactory communication in line of sight $(LOS)$ mode? ........$km$

$A$ transmitting antenna can cover an area of $6.4\pi \times 10^9 \ m^2$ when used for broadcasting. If the signal is transmitted to another antenna,which is at a distance of $100 \ km$ from this antenna,what should be the minimum height of the receiving antenna for satisfactory communication in line-of-sight mode (in $m$)? (Assume the radius of the Earth $R = 6400 \ km$)

Which frequency range is allocated for commercial $FM$ radio broadcasting?