Common types of industrial motor controls include, but are not limited to, combination starter, industrial pump, magnetic coil, magnetic contactor, magnetic starter, manual starter and control relay.
Refraction of Light. Refraction is the bending of a wave when it enters a medium where its speed is different. The refraction of light when it passes from a fast medium to a slow medium bends the light ray toward the normal to the boundary between the two media. The amount of bending depends on the indices of refraction of the two media and is described quantitatively by Snell's Law.
An explanation of why refraction occurs when light travels from a medium with a given refractive index to a medium with another is easily explained by the path integral formulation of quantum mechanics (the complete method was developed in 1948 by Richard Feynman).or example, a light ray will refract as it enters and leaves glass, assuming there is a change in refractive index. A ray traveling along the normal (perpendicular to the boundary) will change speed, but not direction. Refraction still occurs in this case.