$A$ carrier is simultaneously modulated by two sine waves with modulation indices of $0.4$ and $0.3$. The resultant modulation index will be

What is the amplitude of the $LSB$ (Lower Side Band) frequency in the $AM$ wave shown in the figure (in $V$)?

$12$ signals,each band-limited to $5\, kHz$,are to be transmitted by frequency-division multiplexing. If an $AM-SSB$ modulation guard band of $1\, kHz$ is used,then the bandwidth of the multiplexed signal is ....... $kHz$.

For which of the following $AM$ waves is the modulation index equal to $1$?

The antenna current of an $AM$ transmitter is $8 \ A$ when only the carrier is sent,but it increases to $8.96 \ A$ when the carrier is modulated by a sine wave. The percentage of modulation is: (in $\%$)

$A$ signal emitted by an antenna from a certain point can be received at another point on the Earth's surface in the form of: