ELECTRICITY

Electricity is the energy caused by the flow of electrons.

Charge and Static ElectricityChapter 17

Static Electricity : A BUILD UP OF CHARGE (electrons) on an object!

Static electricity by friction and conduction

1. Friction: build up of charge by rubbing one object against another.

Rubbing hair with balloon

2. Conduction: build up of charge by direct contact between 2 objects

Current electricity• Current is a flow of electric charges. It is not a build up of

charge that is discharged.

• All current electricity needs a circuit (a close pathway for electric charges to flow).

• All circuits must have at least 3 parts : 1) wires, 2) a source 3) a load(s).

Parts of a circuit

wires Source of electricity

Load

Conductors

• Conductor: a material that easily allows the flow of electric charges.

• It gives very little resistance to the flow of charge. ( metals – copper, aluminum , etc )

Insulators

• Insulators: They don’t easily allow the flow of electric charges through them.

• Ex: glass, plastic, certain rubber materials, cloth.

WIRE

Types of circuits

• http://www.brainpop.com/science/energy/electriccircuits/http://www.brainpop.com/science/energy/electriccircuits/

Types of circuits

• 1. Series Circuit: only 1 path for the electric charges to flow

• 2. Parallel Circuit: has More than one path for the electric charges to flow.

Series circuit

2. Parallel Circuit: has more than 1 path for electric charges to flow, so if 1 load goes “out,” the other loads will still work !

Draw a parallel circuit

SWITCHES

• A switch is a device that opens or closes a circuit. When you switch on a lamp, you close the circuit. When you switch off a lamp, you open the circuit.