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.
Figure 1. Pencil in glass of water. Refraction is the bending of light rays when they cross an interface between two materials with different refractive indices. For example, when light passes from air into the water at an angle, the light ray will bend toward the normal to the surface.