Electricity : Electricity By Ms. Rosenthal Slide 2: What is electricity? The collection or flow of electrons in the form of an electric charge Slide 3: What is static electricity?
When two objects rub against each other electrons transfer and build up on an object causing it to have a different charge from its surroundings.
Like the shoes rubbing against the carpet. Electrons are transferred from the carpet to the shoes. Slide 4: As electrons collect on an object, it becomes negatively charged. As electrons leave an object it attains a positive charges. Charges interact with each other: Often when you remove clothes from the clothes dryer, they seem to stick together. This is because some of the clothes have gained electrons by rubbing against other clothes. The clothes losing electrons become positive. The negative clothes are attracted to the positive clothes. Have you ever rubbed a balloon on your hair and stuck it on a wall? How do you think this works? Slide 6: The van de Graaf generator (large silver ball) deposits electrons on the ball. When a person places their hand on the ball and the machine is turned on, electrons are transferred to and collected on the person touching the silver ball. Why do you think this machine affects the hair of the children in the picture? Slide 7: What causes you to be shocked when you rub your feet across carpet? An electrical discharge is the passing of an electric current through the air from a negatively charged object to a positively charge object. This is what causes lightning! Slide 8: Check out these static electricity video clips
Static on Baby’s hair
Kid gets static going down a slide What is a conductor and insulator?
A conductor is a material which allows an electric current to pass. Metals, like copper, silver and aluminum are good conductors of electricity.
An insulator is a material which does not allow an electric current to pass. Nonmetals are good insulators of electricity. Plastic, glass, wood, and rubber are good insulators. Slide 9: What is the difference between static electricity and current electricity? Static electricity is stationary or collects on the surface of an object, whereas current electricity is flowing very rapidly through a conductor.
The flow of electricity in current electricity has electrical pressure or voltage. Electric charges flow from an area of high voltage to an area of low voltage. Slide 10: What are electric circuits?
Circuits typically contain a voltage source, a wire conductor, and one or more devices which use the electrical energy.
What is a series circuit?
A series circuit is one which provides a single pathway for the current to flow. If the circuit breaks, all devices using the circuit will fail. Slide 11: What is a parallel circuit?
A parallel circuit has multiple pathways for the current to flow. If the circuit is broken the current may pass through other pathways and other devices will continue to work. Slide 12: What is the difference between an open circuit and a closed circuit?
A closed circuit is one in which the pathway of the electrical current is complete and unbroken.
An open circuit is one in which the pathway of the electrical current is broken. A switch is a device in the circuit in which the circuit can be closed (turned on) or open (turned off).