The digital signals are used for transmission in communication systems. They are

The maximum amplitude of an $AM$ wave is $90 \ V$ and the minimum amplitude is $10 \ V$. What is the modulation index of the $AM$ wave in percentage?

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

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

In an amplitude modulated signal,the maximum amplitude is $15 V$ and the minimum amplitude is $5 V$. The amplitude of the modulating wave will be (in $V$)

Broadcasting antennas are generally