Topic 2: Electricity Within a Circuit Draw a simple diagram of a circuit that includes a control, source, conductor, and a load. Make sure each of the elements are labelled. Hand this in.

You must memorize the following elements and be able to recognize their diagrams. Source: Where the electrical energy comes from. Conductor: The metallic wire the electrons, (current), travels through. Load: Items along the circuit that “use” electrical energy.

Control: A device that connects or breaks the circuit. Cell : A source. This symbol is used for a dry or wet cell.

Battery: A source. This is a combination of cells. Lamp: A load. Since it is so common it has its own symbol. Switch: This is a control. Resistor: A load. Since it is so common it has its own symbol.

***When you draw circuits you must do the following: Use a pencil , ruler, and graph or “white” paper. Draw a square or rectangular circuit Ensure your conductors DO NOT cross. Be neat and make symbols the same size. Current This is the amount of charge, (electrons), that travels per second. Symbol: I Unit: Amperes (A) or milliamperes (mA)

Current Continued Measuring Devices: Galvanometer (weak current) 2. Ammeter (larger currents) *** You must connect both these meters in series. ***

Voltage This is the common name for potential difference. It is the difference in energy per unit charge between two points in a circuit. Symbol: V Unit: volts (V) Measuring Device: 1. Voltmeter *** You must connect these in parallel. Read page 488 – 490 & complete “Instant Practice” pg. 490