Smasher

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Hello there, I am Smasher. Sparky, Slippery, Smiley, and myself will be assisting you as we learn about the electrical properties and components.

Dr. Gary Stewardson, Raymond Boyles

Smasher

Sparky Slippery Smiley

Properties of Electricity

Hi, Slippery here. We are going to discuss some of the properties of electricity. You will need to take PowerPoint Guided Notes.

These notes will be useful later to complete your activity sheet.

2Dr. Gary Stewardson, Raymond Boyles


Smasher here. I wanted to let you know that electricity has three properties. They are:

• Voltage – the amount of pressure pushing the electricity through a circuit.

• Current – the amount of electricity flowing at a given rate through a circuit.

• Resistance – the opposition to the flow of electricity through a circuit.



Another way to understand the properties of electricity is by comparing electricity to the behavior of water from a garden hose. Sparky will explain this section.


Voltage

When the water tap is turned on, the release of water creates pressure. The more the tap is turned, the greater the pressure. This pressure can be compared to electricity’s property of voltage. Voltage is the amount of pressure pushing the electricity through a circuit.


Current

The rate at which the water flows from the reservoir can be compared to electricity's property of current.


CurrentCurrent is the amount of electricity flowing at a given rate. The greater the flow of water, the greater the rate. This rate of flow can be compared to electricity’s property of current.

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Higher Pressure – Higher Flow Rate Lower Pressure – Lower Flow Rate

Dr. Gary Stewardson, Raymond Boyles

Resistance

The nozzle on the garden hose can be compared to electricity's property of resistance. As we close the nozzle, we increase the resistance to the flow of water. Resistance in an electrical circuit is the opposition to the flow of electricity through a circuit.


Nozzle

Components in a Circuit

Now that we discussed the three properties of electricity, let’s talk about electrical components, their purpose, and their symbols. Slippery will explain the components.


Battery

A battery is used to supply the electricity. The battery we used when testing for conductivity is shown below. This battery is rated at 1.5 volts (electrical pressure). The symbol for the battery is on the bottom right of this slide. We use symbols so we can easily draw the representation instead of drawing the component.

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Battery Schematic symbol for a batteryDr. Gary Stewardson, Raymond Boyles

Power Sources

Remember, we said that a battery can be used to supply electricity. There is another device that can supply electricity as well. This device is known as a power supply. So a battery and a power supply are similar in that they are both power sources. They also use the same symbol. Smiley is pointing to the power supply.

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Power Supply Schematic symbol for a Power SupplyDr. Gary Stewardson, Raymond Boyles

Light Bulb

A light bulb produces light. When electricity passes through the bulb, the filament (wire) resist the flow of electricity and increases in temperature. The resistance of the filament causes the filament to glow and emit light.

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Light Bulb Schematic Symbol for a Light BulbDr. Gary Stewardson, Raymond Boyles

Hook-up Wire

Hook-up wire provides a path for electricity to flow from one component to another. The hook-up wire we use has a color coating on the outside of the wire. This coating is an insulator. The insulation helps keep electricity from changing paths. The symbol for wire is simply a line connecting various components.

13 Wire Schematic symbol for WireDr. Gary Stewardson, Raymond Boyles

Electrical Switch

A switch is an electrical component that can open or close an electric circuit interrupting or allowing the flow of electricity.

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Knife Switch Schematic symbol for a switchDr. Gary Stewardson, Raymond Boyles

Electrical Switch

An open circuit does not allow electricity to flow.A closed circuit allows electricity to flow.


No flow of electricity (Open) Flow of electricity (Closed)

Light Bulb Circuit Board

Since we know that we need a switch and a light bulb for our activities, why don’t we just use a device that already has both electrical components attached. This device is known as a Light Bulb Circuit-Board.


Activity 4

Now that we have completed the PowerPoint and your guided notes you should be able to complete Activity 4: Electrical Properties and Components.


Smasher

Documents

gary stewardson

flow of electricity

raymond boyles voltagewhen

raymond boyles currentcurrent

raymond boyles currentthe

rate of flow

flow of water

electrical properties