Radio waves

Light waves with shorter wavelengths (and higher frequencies) also have more energy, so types of light like gamma rays, X-rays, and ultraviolet light are more energetic than visible light, and infrared, microwaves, and radio waves are less energetic than the light in the visible spectrum.

Since violet light has a shorter wavelength, it is slowed more than the longer wavelengths of red light. Consequently, violet light is bent the most while red light is bent the least. This separtion of white light into its individual colors is known as dispersion of light.

Red has the highest wavelength and violet the lowest. Wavelength is inversely proportional to the deviation in the path of the light. The color red therefore deviates the least since it has maximum wavelength and color violet deviates the most since it has the least wavelength.

For stopping the vehicles moving on the rod, we use the light as a traffic signal. So the scattering is inversely proportional to the fourth power of wavelength of the light. As the wavelength of red light is maximum, so it is least scattered by the atmospheric particles. Therefore it is used in traffic signals.

The red light has a single wavelength and when enters a prism, it will not split into other different colours.

If the red light is produced by a source that provides only red wavelengths of light (e.g. a red laser), then the prism cannot spread that out into different colours at all.

When light travels from air into water, it slows down, causing it to change direction slightly. This change of direction is called refraction. When light enters a more dense substance (higher refractive index), it ‘bends’ more towards the normal line.