The process of superimposing a signal frequency (i.e.,audio wave) on a carrier wave is known as:

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

The mathematical form of an $AM$ wave is given by $e = 50 (1 + 0.5 \sin(2\pi \times 5 \times 10^{3} t)) \sin(31.4 \times 10^{6} t) \text{ V}$. The modulation index of the given $AM$ wave is .......

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

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

In amplitude modulation,the amplitude of the carrier wave is $A_c$ and that of the modulating signal is $A_m$. In practice,the ratio of $A_m$ to $A_c$ is kept less than or equal to $1$ to avoid: