Rheostat, a device used to regulate an electric current by increasing or decreasing the resistance of the circuit. Some common uses of the rheostat are to dim lights, to control the speed of an electric motor, and to control the volume of a radio. The accompanying diagram shows a simple rheostat. Current flows into the resistance coil and from the resistance coil through the slider. When the control knob is turned, the slider moves along the coil; the amount of resistance is thus changed by varying the length of the current's path through the resistance coil.
You Might Also Like
Compounding pharmacies don't usually get a lot of media coverage for good news. It's the mistakes that tend to make the evening news. It turns out that U.S. regulatory practices for compounding pharmacies tend to follow much the same pattern.
Bullets, wires and nails are all measured with unusual measurement systems and units -- and they all show just how interesting measurement systems can be!