What is the frequency of an $FM$ transmitter without a signal input?

For $100\%$ modulation,what should be the value of the minimum amplitude $(E_{min})$ of the modulated wave?

The wavelength of the carrier waves in a modern optical fiber communication network is close to ........ $nm$.

The characteristic impedance of a coaxial cable is typically ...... .

$A$ carrier signal $C(t)=25 \sin(2.512 \times 10^{10} t)$ is amplitude modulated by a message signal $m(t)=5 \sin(1.57 \times 10^{8} t)$ and transmitted through an antenna. What will be the bandwidth of the modulated signal?

Space wave propagation is possible for which frequency range?