Basic Circuits

What is a circuit? An electric circuit is a complete path through which charge can flow.

Parts of a Circuit Wire – any material that allows charge to flow freely through it. Used to connect parts of a circuit; does not need to be specifically mentioned. Symbol:

Parts of a Circuit Generator / Battery / Motor – a source of energy for the circuit. Symbols:

Parts of a Circuit Light bulb: Any source of visible light caused by increased resistance releasing energy as heat. Symbol:

Parts of a Circuit Ammeter – Instrument that measures the current (amps) of a circuit. Symbol: Voltmeter- Instrument that measures the voltage of a circuit

Parts of a Circuit Switch: An electrical component that can break the flow of current in a circuit. Symbol:

Parts of a Circuit Resistors – an electrical component that resists the flow of electrons. Symbols:

Open Circuit An open circuit is not a completed loop. No current can flow in an open circuit.

Closed Circuit A closed circuit is a completed loop through which electricity can flow. Current occurs in closed circuits.

Short Circuit A short circuit is any path that allows very low resistance to occur. Commonly, it happens when the positive and negative terminals of a battery are connected with a wire.

Short Circuit Short circuits can be very dangerous because they can cause the wire to over-heat and start a fire.

Series Circuit A series circuit has only one path for the electrons to flow through.

Parallel Circuit Parallel circuits have multiple paths for electrons to flow.