Direct current is constant over time; alternating current alternates smoothly back and forth over time Circuit diagrams are schematic representations of electric circuits

The equivalent resistance of a group of N identical resistors R connected in parallel is R / N Electrical resistance causes materials to extract work from the current that flows through them

in parallel — when a group of resistors are connected side by side, with the top ends of the resistors connected together by a wire and the bottom ends connected together by a different wire. in series — when elements in a circuit are connected one after the other in the same branch of the circuit. circuit diagram — schematic drawing of an electrical circuit including all circuit elements, such as resistors, capacitors, batteries, and so on. resistance — how much a circuit element opposes the passage of electric current; it appears as the constant of proportionality in Ohm’s law.