1. Electric Current & Electric Circuits

2. The movement of electrically charged particles is an electric current. The SI unit for electric current is ampere or amp. A closed, or complete, path in which an electric current travels is an electric circuit.

3. The lightbulb glows as electrons flow from one end of the battery, through the wires and lightbulb, and back into the other end of the battery.

4. Resistance Electric resistance is a measure of how difficult it is for an electric current to flow in a material. A good conductor has a low resistance and a good insulator has a high resistance. A material’s electric resistance depends on the material’s length and thickness. The longer the length or the thinner the wire, the greater the resistance.

5. Types of Circuits A series circuit is an electric circuit with only one path for an electric current to flow. A parallel circuit is an electric circuit with more than one path for an electric current to flow.