p.448-452

A way of drawing an electric circuit using standard symbols

Some symbols require you to identify the positive and negative terminals

e.g. Dry cell, motor, and DC power supply

Fuse A device used to protect against excessive current

Lamp* A device that changes electrical energy into another form (light, heat, sound)

Resistor A device that resists the flow of current

Ammeter An instrument that measures the electric current (Flow of charge per unit time)Placed within the circuit

Voltmeter An instrument that measures the potential difference between 2 points Placed around a load/battery

Flow of electrons follows only one path

E.g. Plugging in a toaster and an electric kettle in the same outlet are loads on the same circuit

Electrons can flow more than one way Loads are on at least two different

branches of wires that connect to an energy source

After reaching a branch, the electron flow splits and then merge again before returning to the energy source

E.g. Most homes, buildings are connected in parallel

CIRCUIT Voltage (V)

Current (I)

Resistance (R)

SeriesIf one load off ALL loads off

Each load uses a portion of V supplied by the battery(brightness decreases as more loads added)

Current is the same throughout circuit

Current decreases when more resistors are added

ParallelIf one load off remaining loads stay on

Each load uses all the V from battery(brightness stays the same even as more loads added

Current divided between the pathways for loads

Adding resistors in parallel decreases total current of circuit

Read and supplement notes section 11.2

Complete: p. 450 #1,3,4 P. 453 #1-4 P. 457 #3,4