define: ground
In electrical engineering, ground or earth is the reference point in an electrical circuit from which voltages are measured, a common return path for electric current, or a direct physical connection to the Earth. Electrical circuits may be connected to ground for several reasons. In mains powered equipment, exposed metal parts are connected to ground so that if, due to any fault conditions, a Line supply voltage connection occurs to any such conductive parts, the current flow will then be suc