Q.Mention the frequency of radio waves.

To send a message through free space, information is first turned into electromagnetic (radio-frequency) waves — sinusoidal oscillations in which a time-varying electric field and magnetic field lie perpendicular to each other and to the direction of travel. These waves radiate outward and travel at the speed of light, $3\times10^{8}$ m/s, making them ideal carriers for both short- and long-distance communication.

The radio portion of the electromagnetic spectrum spreads over an enormous range of frequencies, from about $10^{4}$ Hz to $10^{14}$ Hz. Rather than treat this as one continuous block, it is divided into named frequency bands, each with its own propagation behaviour and typical uses: