Electric Energy (Electricity) A form of energy that is produced when electrons move from one place to another

Circuit Circuit: a closed path an electric current flows through Necessary in order for electric charge to move. Key part of circuit… know what it is? A circuit always needs a power source, such as a battery, with wires connected to both the positive (+) and negative (-) ends. Electricity will only travel around a circuit that is complete. That means it has no gaps. If switch is open, current will not flow. If switch is closed, current will flow.

Electric Current The constant flow of electrons through a conductor

Open Circuit Circuit that is not connected in some area, so electrons do not flow through. Electricity is off.

Open Circuit

Closed Circuit Complete circuit that allows electrons to flow through completely. Electricity is on.

Closed Circuit

Circuits Two kinds: Series: current has only one path to travel through Ex. Flashlight, holiday lights Parallel: contains more than one path for current to travel through. Ex. House, school Make sure to point out in these pictures the battery, light bulbs, wire/conductor, and the switch. Note in both of these pictures that the switch is closed, therefore the light bulbs are on. SERIES: In a television series, you get several episodes, one after the other. A series circuit is similar. You get several components one after the other. In a series circuit, if a lamp breaks or a component is disconnected, the circuit is broken and all the components stop working. Series circuits are useful if you want a warning that one of the components in the circuit has failed. They also use less wiring than parallel circuits PARALLEL: different components are connected on different branches of the wire. In a parallel circuit, if a lamp breaks or a component is disconnected from one parallel wire, the components on different branches keep working. Useful if you want everything to work, even if one component has failed. This is why our homes are wired up with parallel circuits.

Series vs. Parallel Series: Parallel: One branch/path Simpler All components must work at same time. One break stops the flow of the current Current is the same throughout the circuit (lights are equal brightness). Parallel: Multiple branches/paths More complex Can use one component at a time. One break does not stop the flow of the current Current split among each pathway – takes path of least resistance. (a bigger light would be dimmer)

 DIFFERENCES BETWEEN SERIES & PARALLEL CIRCUITS Click on the light switches to turn the globes on and off. Note the relative brightness of globes. Click on an illuminated globe to “break” it. Note the effect. Click red arrow to reset (repair globes). Click elsewhere to proceed to next slide. 

Drawing Circuits When drawing circuits, symbols are used. Wires are shown as straight lines

Series and parallel circuit Drawing Circuits Basic notation to know: Parallel circuit (3 pathways) Series circuit (1 pathway) Series and parallel circuit I like to show this first to give them a general idea of how to even get started with drawing. I always tell them to just draw a rectangle for a series circuit. Parallel add more branches to that rectangle. I won’t have CP ever draw a combo circuit, and for honors it would only be bonus.

Drawing Circuits Basic notation to know: Switches Battery Resistor (closed) (open) (one) (two) Resistor Light bulb Ammeter Measures amount of current (Only in series circuits) Voltmeter Measures the voltage drop (Only in parallel circuits) You won’t have to know how to draw a resistor, ammeter, voltmeter. You are only responsible for knowing switches, light bulb and battery or or

Example #1 Draw a series circuit with a battery, two light bulbs, and an open switch. Note: order doesn’t matter on a series circuit!

Example #2 Draw a parallel circuit with two batteries, two light bulbs (on separate branches), and a switch that could turn off the whole circuit.

Guided Practice Time Draw a series circuit with two batteries, a light bulb, and a closed switch. Draw a parallel circuit with two batteries, 3 light bulbs, and 3 switches. Each light should be able to be turned off individually.