The modulation index for an $A.M.$ wave having maximum and minimum peak-to-peak voltages of $14\,mV$ and $6\,mV$ respectively is:

$A$ signal $A \cos \omega t$ is transmitted using $v_0 \sin \omega_0 t$ as a carrier wave. The correct amplitude modulated $(AM)$ signal is:

The required height of a $TV$ tower which can cover the population of $6.03$ lakh is $h$. If the average population density is $100$ per square $km$ and the radius of the Earth is $6400 \, km$,then the value of $h$ will be $... \, m$.

$A$ diode detector is used to detect an amplitude modulated wave with $60\%$ modulation,using a capacitor of $250 \ pF$ in parallel with a resistor of $100 \ k\Omega$. What is the maximum modulation frequency that can be detected by this circuit?

If the height of transmitting and receiving antennas are $80\,m$ each,the maximum line of sight distance will be $..............\,km$. Given: Earth's radius $= 6.4 \times 10^6\,m$.

$A$ $TV$ transmitter has a range of $50 \ km$. The height of the $TV$ transmitter is $......$ (Radius of the earth $R_e = 6.4 \times 10^6 \ m$) (in $m$)