CIRCUITS AND

Standards SPI Identify how simple circuits are associated with the transfer of electrical energy when heat, light, sound, and chemical changes are produced.

What is Electricity? form of energy Like sound and light, electricity is a form of energy. Electrical energy can change into other forms of energy such as heat, light, sound, and energy of motion. These changes can take place like a path within a system that acts like a path in which electrical energy can flow.

Parts of an Electrical Circuit energy of charged particles in matter Electrical energy is the energy of charged particles in matter. It can be used to make light, heat, make things move (like an electric fan), etc. To get electrical energy to go where you want it to go, you must give it a path to follow… a path for the flow of electricity An electrical circuit is a path for the flow of electricity. Humans set up electrical circuits so that they can transform electric energy into the other forms of energy they want to use.

Parts of an Electrical Circuit An electrical circuit has 3 main parts. 1. A Source of Electrical Energy 2. An Output Device 3. Connectors between the two BatteriesWire Light bulb

Parts of an Electrical Circuit anything that supplies electricity Batteries An electrical source can be anything that supplies electricity. When you plug in a lamp into the wall, you are plugging it into an electrical source. Batteries are also electrical sources. use An output device is anything that can use the electricity. A light bulb, toaster oven, an alarm, and a fan are all examples of output devices. connectors The connectors are usually wires.

In the circuit below, what is the electrical source? The battery What is the output device? The light bulb Wires connect the two, completing the circuit, creating electric current. an electric current.

This circuit shown below should work. But a circuit like this has a problem. Electrical energy would flow until the battery ran out of energy. You would not be able to turn the light off without breaking the circuit. This is why most circuits have a way of turning the flow of electrical current on switch and off. A switch is a device that opens and closes a circuit.

switch Instead of just wires connecting the battery directly tothe light bulb, in this example there is a switch, made of metal like the wire, that can be used to open and close the circuit. When the circuit is closed, the electrical current can pass through.

Open and Closed Circuits closed circuit break in the flow A closed circuit is a complete path for the flow of electricity. A closed circuit does not have any break in it. An open circuit has a break in the flow of electricity.

Open and Closed Circuits Which picture shows an open circuit? Closed circuit? Closed! Open!

This switch works the same way a light switch works.

Series vs. Parallel Circuits Series circuits 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. If you follow the circuit diagram from one side of the cell to the other, you should pass through all the different components, one after the other, without any branches. One big loop Series = One big loop

Series vs. Parallel Circuits Series circuits If you put more lamps into a series circuit, the lamps will be dimmer than before. In a series circuit, if a lamp breaks or a component is disconnected, the circuit is broken and all the components stop working.

Series vs. Parallel Circuits Parallel circuits In parallel circuits different components are connected on different branches of the wire. If you follow the circuit diagram from one side of the cell to the other, you can only pass through all the different components if you follow all the branches.

Series vs. Parallel Circuits In a parallel circuit, if a lamp breaks or a component is disconnected from one parallel wire, the components on different branches keep working. And, unlike a series circuit, the lamps stay bright if you add more lamps in parallel.

Energy Changes in Circuits soundheat The wires in the walls of your home form circuits. When you plug in a fan, the fan becomes part of one of those circuits. The form of energy that electrical energy changes into depends on the output device. Your fan changes electrical energy to mechanical energy, in the moving fan blades. But not all of the energy moves the blades. If you are close, you can hear it turning. It may also become warm after a while. This indicates that some of the electrical energy that flows into the fan turns into sound and heat energy.