The radio horizon of a transmitting antenna of height $39.2 \ m$ is (Radius of the earth $= 6400 \ km$) (in $km$)

An $AM$ wave has $1800 \ W$ of total power content. For $100 \%$ modulation,the carrier should have a power content equal to $...... \ W$.

Ground waves are polarized in which direction?

$A$ $TV$ tower has a height of $5 \, m$ in a region of population density $\frac{1000}{\pi}$ per square kilometre. The number of people that can receive the transmission is nearly, (in thousands)

The frequency range for commercial $FM$ radio broadcasting is .......

$A$ carrier signal of frequency $v_1$ and peak voltage of $V_1$ is modulated by a message signal of frequency $v_2$ and peak voltage of $V_2$. Let $m$ be the modulation index and $v_{+}, v_{-}$ be side bands produced. The correct statement is