An antenna current of an $AM$ broadcast transmitter modulated by $50\%$ is $11\, A$. The carrier current is.........$A$.

An amplitude modulated wave is represented by $10[1+0.6 \sin(40 \times 10^3 t)] \sin(4 \times 10^6 t)$ volt,where $t$ is in seconds. The ratio of the upper sideband frequency to the lower sideband frequency is:

Consider an optical communication system operating at a wavelength of $\lambda \sim 800 \, nm$. If only $1\%$ of the optical source frequency is available for optical communication,how many channels can be accommodated for a bandwidth of $8 \, kHz$?

This question has Statement-$1$ and Statement-$2$. Of the four choices given after the statements,choose the one that best describes the two statements.
Statement-$1$: Sky wave signals are used for long-distance radio communication. These signals are,in general,less stable than ground wave signals.
Statement-$2$: The state of the ionosphere varies from hour to hour,day to day,and season to season.

$A$ radio can tune to any station in the $6\,MHz$ to $10\,MHz$ band. The value of the corresponding wavelength bandwidth will be $....\,m$.

$A$ $500\, Hz$ modulating voltage fed into an $FM$ generator produces a frequency deviation of $2.25\, kHz$. If the amplitude of the voltage is kept constant but the frequency is raised to $6\, kHz$,then the new frequency deviation will be.......$kHz$.