The characteristic impedance of a coaxial cable is of the order of .......... $\Omega$.

$A$ message signal of frequency $14 kHz$ is used to modulate a carrier of frequency $900 kHz$. The frequencies of the sidebands are:

An amplitude modulated wave is represented by the expression $v_{m}=5(1+0.6 \cos 6280 t) \sin (211 \times 10^{4} t) \; V$. The minimum and maximum amplitudes of the amplitude modulated wave are,respectively:

The process of superimposing a signal frequency onto a carrier wave is known as .......

The $T.V.$ transmission tower in Delhi has a height of $245 \ m$. The distance up to which the broadcast can be received (taking the radius of the earth to be $6.4 \times 10^6 \ m$) is .......... $km$.

Range of frequencies allotted for commercial $FM$ radio broadcast is