The wire that carries the current from the power source to the outlet or receptacle is the hot wire. Whenever you see a black wire, you know it is hot. There are other wires that carry current in more complicated circuits, but black are always hot.
Total Internal Reflection and the Critical Angle. If a ray of light is leaving a denser medium, it will bend away from the normal. As can be seen from the above diagram, as the angle of incidence inside the material increases the angle of refraction increases to a point at which it leaves the material at 90Ë.
Definition. No. If there is no change in speed there is no refraction. If there is no refraction, there is no dispersion of light and hence, no rainbow! Term. The minimum angle of incidence for which a light ray is totally reflected within a medium is called the ______________ _______________. Definition. critical angle. Term. The 100% reflection (with no transmission) of light that strikes the boundary between two media at an angle greater than the critical angle is called _______ ________ ________.