What does refraction of an RF signal involve? a. Conversion of signal energy into heat b. Changing speed and bending between media of different densities c. Splitting into multiple signals d. Bouncing off a smooth surface

The correct answer is b. Changing speed and bending between media of different densities.<br /><br />Refraction of an RF (radio frequency) signal involves the change in speed and bending of the signal as it passes through different media with varying densities. When an RF signal travels from one medium to another, such as from air to water or from air to glass, the speed of the signal changes due to the difference in the refractive index of the two media. This change in speed causes the signal to bend or refract.<br /><br />The refractive index is a measure of how much the speed of light (or any electromagnetic wave) is reduced inside a medium compared to its speed in a vacuum. When an RF signal enters a medium with a higher refractive index, it slows down and bends towards the normal (the imaginary line perpendicular to the surface). Conversely, when the signal enters a medium with a lower refractive index, it speeds up and bends away from the normal.<br /><br />This phenomenon of refraction is important in various applications, such as in the design of antennas, waveguides, and optical fibers, where the bending of RF signals is utilized to direct and control the signal propagation.