Unit 5 - Electricity

StandardSPS10. Students will investigate the properties of electricity and magnetism.

EQ: How do you relate electron movement to static electricity?

Do now! Take 5 minutes to review your information on Static electricity

Agenda

1. Do now! Quiz

2. Vann Der Graph generator activity

3. Current Electricity Notes

4. Check point Quiz Questions

5. TOTD

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What is Electricity?• Electricity is the movement of electrons

• Remember:

• All matter is made up of atoms.

• Two of the particles in atoms are electrically charged.• The protons, which are

tightly held in the nucleus, are positively charged.

• They are fixed and do not move

• The electrons, which move around outside the nucleus, are negatively charged.

• They are fixed and can move around

Static ElectricityWhen objects rub together, the electrons in the atoms can be knocked off and move onto something else.

When an object loses electrons it will have more protons than electrons and will have a positive charge

If an object gains electrons it will have more electrons than protons and will have a negative charge.

Both the rag and the plastic rod now have a

Static Electric Charge

Static ElectricityWhen a static electric charge builds up on an object, it would cause the object to react to it’s surroundings .

This is what happens in a thundercloud whena charge builds up and discharges as lightening!

Or cause the object to discharge it’s excess electrons as a static shock.

Static Electricity causes Hair to stand up!

Static Electricity is being transferred between the pin heads

Lightening is a very large static electric discharge!

Checkpoint 1

1. What causes static electricity?

2. How is static electricity created?

3. Explain why static causes hair to stand up.

4. How is lightening is formed?

5. Explain in three steps, why a balloon sticks to a wall after it is rubbed on

someone's hair

Electric Current

Electric current is measured in amperes or amps.

A conductor is any material that allows electricity to flow through it.

Example: a piece of metal

The metal is made up of atoms that have electrons moving in the clouds around the nuclei

Electric current is the flow of electrons through a conductor.

The symbol is (a).

Electron Flow Electron Flow

Checkpoint 2

1. What causes static electricity?

2. How is static electricity created?

3. Explain why static causes hair to stand up.

4. How is lightening is formed?

5. Explain in three steps, why a balloon sticks to a wall after it is rubbed on someone's hair

6. What is current electricity?

7. Why are Metals good conductors?

8. Why do we use a circuit diagram?

9. Construct a Venn type graphic organizer comparing and contrasting Parallel and series circuits.

Electric Circuits A circuit is a path that electric current flows through.

A circuit

Wires and various components connected together form a circuit.

Circuit diagrams use symbols to show how all the components connect together to make a circuit

wire

A circuit diagram

Battery

Lamp

Switch

wire

=

Types of Circuits There are two types paths that electric current flows through.

• A series circuit is one in which the components are in line with each other and the wires.

• There is only one path for the current to flow.

A series circuit

Parallel circuit

• A parallel circuit is one in which the components are connected parallel with each other.

• There is more than one path for the current to flow.

A parallel circuit

Voltage Voltage is the energy that pushes and pulls electrons through the circuit.

Voltage can be created by a battery ( also called a cell ) when it changes chemical energy to electrical energy

Or by a generator when it changes mechanical energy to electric energy.

Voltage is measured in volts. The symbol is (v).

Voltage is measured using a voltmeter

Resistance

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• Resistance happens when the electrons flowing through the wire continually run into things in the wire and bounce around.

• Resistance opposes the flow electrons through a conductor.• It is measured in ohms. The symbol is Ω .

• Resistance will slow the flow of current because it makes it harder for the current to get through the wire.

OHM'S LAWOhm's Law is used to describe the mathematical relationship between voltage, current, and resistance.

I = V/R,

I = current, V = voltage, and R = resistance

Direct current (DC):

• DC current or direct current flows in one direction.

• DC current can be produced using a solar cell or a chemical cell ( battery)

Alternating current (AC):

• AC current or alternating current moves back and forth.• The electric current that comes out of the outlets in our

homes and schools is AC current.

• AC current can be produced by a generator using the principle of electromagnetic induction.

• The current is produced when a magnet moves relative to a coil of wire.