The height of the transmitting antenna,if $TV$ programs have to cover a population in an area of radius $64 \ km$,is: [Use Radius of earth $= 6.4 \times 10^6 \ m$] (in $m$)

For an amplitude modulated wave,the maximum amplitude is found to be $10 \,V$ while the minimum amplitude is found to be $4 \,V$. The modulation index is

An oscillator is producing $FM$ waves of frequency $2 \text{ kHz}$ with a frequency variation of $10 \text{ kHz}$. What is the modulation index?

The height of a $TV$ tower is $150 \ m$. If the population density in the area covered by the $TV$ tower is $50 \ \text{lakhs}$, then the population density around the $TV$ tower is ....... $km^{-2}$. (Radius of the Earth is $6.4 \times 10^{6} \ m$)

The total power in an $AM$ wave is $1500 \ W$. What is the power transmitted by the carrier for $100\%$ modulation (in $W$)?

For radio and television broadcasting,what type of signals are used to carry information?