The maximum amplitude of an $AM$ wave is $90 \ V$ and the minimum amplitude is $10 \ V$. What is the amplitude of the modulating wave in the given $AM$ wave (in $V$)?

The height of the transmitting antenna is $180\,m$ and the height of the receiving antenna is $245\,m$. The maximum distance between them for satisfactory communication in line of sight will be .......... $km$ (given $R = 6400\,km$).

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 $m$)

The number of amplitude modulated broadcast stations that can be accommodated in a $300\, kHz$ bandwidth for the highest modulating frequency of $15\, kHz$ is:

The maximum peak-to-peak voltage of an $AM$ wave is $24 \, mV$ and the minimum peak-to-peak voltage is $8 \, mV$. The modulation factor is.....$\%$

Which one of the following is not classified as pulse modulation?