ELECTRICITY Unit Test Study NOTES

Unit Test on: Definitionscircuit

- the pathway that the electric current follows.- Circuits must have a source of energy (eg. a battery), a pathway (eg.

wires), and an output device (eg. Lights, heater, motor, etc). - An open circuit will not allow the electricity to flow (the switch is open,

or the circuit is not complete). A closed circuit will allow electricity to flow.

conductor – a material that allows electricity to flow through it very easily.

insulator – a material that doesn’t allow electricity to flow through it easily.

* You will need to be able to identify various materials that are conductors or insulators.

Resistor - A resistor is something that might be added to a circuit that resists the flow of electricity, allowing less to flow through.

electricity – a form of energy that can produce heat, light, magnetism and electrical charges.

static electricity – electricity at rest or electricity that is not moving.

current electricity- the flow of electrons moving constantly in one direction.

electrical energy- a type of energy that can be converted into heat and light.

The Law of Electrostatics – Like charges repel and unlike charges attract.

Series Circuit (NOTE: You will be required to identify this.)A series circuit consists of a single pathway for an electric current that contains more than one electrical (output) device. If one bulb goes, out they all go out.

battery

closed switch

Parallel Circuit (NOTE: You will be required to identify this.)A parallel circuit consists of two or more electrical devices arranged on separate circuits so that each device can work independently (by itself). If one bulb goes, out the others stay lit.

battery

open switch

light bulb closed switch

light bulb

Atoms• Every living and nonliving thing is made up of atoms.

• Atoms are so small that millions of them would fit on the period at the end of this sentence.

• In the center of every atom is a nucleus which contains tiny particles called protons (protons are positive).

• Electrons are even smaller particles and they orbit around the nucleus.

• Protons have a positive charge.

• Electrons have a negative charge.

IMPORTANT PEOPLE:

Thales: A Greek man who discovered that if he rubbed a piece of amber with a silk cloth, the amber would attract small bits of grass, feathers and other light objects. By doing this he discovered that objects could become electrically charged.

Benjamin Franklin: • Benjamin Franklin was very interested in electricity. He believed that lightning was caused by electricity and performed experiments to prove it.

• In 1752, he picked a day when there was about to be a storm. He fastened a stiff wire to a kite and at the end of the kite string, he tied a key. As it rained, the wet string of the kite began to conduct electricity. Sparks jumped from the key. Franklin proved that lightning was really a large spark of electricity, but he was fortunate not to have been killed.

Thomas Edison

• Edison is best known for inventing the phonograph and the first light bulbs that were practical and safe to use.

• In Edison’s time streets and buildings were lit by gas lamps. Edison was very interested in finding a way to generate light using electricity.

• In 1879 Edison successfully created the first incandescent light bulb. He had to use a metal called tungsten for the filament of the bulb.

Circuit Drawing Symbols:

What is a Magnet?

God created magnets. Man did not create them. God created the earth to be a

magnet and He set the universe in place. Magnets only stick to four metals. The first

three are iron, nickel, and cobalt. Because steel is a combination of

different metals and has iron in it, magnets will stick to steel. Metals that magnets do

NOT stick to include gold, silver, lead, zinc, copper, aluminum, and brass. It does not

matter what the object is. It only matters what it is made of. Magnetism occurs in iron,

cobalt or nickel because the atoms in the metals are arranged randomly.

• The word attract is used when two magnets pull together.

• The word repel is used when two magnets push apart.

Electromagnets

An electromagnet is made when an electrical charge flows through a wire, causing the wire’s atoms to line up and turn into a temporary magnet. Look in your workbook for more information. What happened in our electromagnet experiment?

How is Electricity GeneratedRead the handout in your workbook about how electricity is generated.

- You will need to explain how we create current electricity (electricity that moves) to use in our houses

1. Giant generators create current electricity a. Hydroelectric Power Plantsb. Fossil Fuel Power Plantsc. Nuclear Power Plantsd. Wind Turbine generation of electricity

In all of these types of Power Plants, a turbine needs to be turned to create electricity. Often water is heated up and steam moves the turbine, but sometimes water or wind will move it.

2. The electricity created is put through a transformer that steps up the power to a higher voltage so it can travel further.

3. When it arrives at it’s location, the electricity goes through another transformer at a sub station to step the power down a little more.

4. Finally, the electricity goes through another transformer at your house to step the electricity down to a level that is appropriate to be used at your house. You now have electricity to use at your house!

YOU WILL NEED TO BE ABLE TO GIVE DETAILS ON HOW ELECTRICITY IS GENERATED!