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.
The minimum angle at which total internal reflection occurs is known as the critical angle (for Perspex this is about 43Ë). At any angle greater than the critical angle, total internal reflection occurs and the light ray obeys the normal rules for reflection (i.e. angle of incidence = angle of reflection). 1  Page. 2  1. 3  2.
Regular Reflection. If a parallel beam of light is reflected as a parallel beam, when it strikes on a smooth and polished surface, then it is called regular reflection. Plane Mirror: Looking glass, polished metal surfaces, mercury surface and smooth surface of water are all called plane mirrors. Irregular Reflection: If a parallel beam of light is reflected as in different directions, when it strikes on a rough surface, then it is called irregular reflection.