For an amplitude modulated wave,the modulation index is found to be $0.5$. If the maximum amplitude is found to be $10.0 \ V$,then the minimum amplitude is: (in $V$)

The heights of transmitting and receiving antennas are respectively $\frac{1}{20000}$ and $\frac{1}{80000}$ times the radius of the earth. The maximum distance between these two antennas for satisfactory communication in line of sight mode is (Radius of the earth $= 6.4 \times 10^6 \ m$) (in $km$)

$A$ carrier wave of peak voltage $12 \, V$ 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 $75 \%$? ...... $V$

$A$ 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

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

If a $TV$ transmission antenna covers a radius of $128 \, km$,what should be the height of the antenna in $m$?