Electricity

All matter is made up of positive charges and negative charges.

Electricity The positives have mass and are not usually free to move.

Electricity The negatives have no mass and are free to move through some materials (conductors).

Electricity Good Conductors do Not hold on to their valence electrons well – ex. metals

Electricity Negative charges are attracted to positive charges like mice are attracted to cheese. _ +

Static Electricity Build up of Electrons creating Electric Charge Created By: –Friction –Induction –Conduction

Static Discharge

Electricity Any time there is a natural attraction between two things we can use it to make the objects do work. The negative charges (mice) will gladly do work in order to get to the positive charges (cheese). + _

Electricity Voltage: – The amount of work that each charge (mouse) will do as it goes through the circuit. –the amount of push on the charges or –how hungry the mice are. _ +

Electricity Resistance: The opposition to the flow of charge. Any appliance that asks the charge (mouse) to do work will slow it down. _

Resistance Decrease –Short wire –Thick wire –Cooler wire Increase –Long wire –Thin Wire –Warm Wire _ _ _ _ _ _ __ _ _ _ _ _

Electricity Current: – The number of charges (mice) passing a point per second. The rate of flow of charges. _ _ _ _ _ _

Electricity D Battery 1.5 voltes & 15 amps _ _ _ _ _ _ _ _

Electricity AA Battery 1.5 voltes & 2.8 amps _ _ _ _ _ _ _ _

Electricity This set up has a voltage (desire on the part of the mouse) but no current flows because there is no conductive path. It has the ability to do work but no way to get there. _ +

Circuits Series –One Path for e- Parallel –2 or more Paths for e- __ _ _ _ ___ _ _ _ __ _ _ _ ___ _ _ _ ___ + +

Circuits Series –One Path for e- –Add Resistors then Current Decreases Parallel –2 or more Paths for e- –Add Resistors then Current Increases __ _ _ _ ___ _ _ _ + __ _ _ _ ___ _ _ _ ___ +

Circuits Series –One Path for e- –Add Resistors then Current Decreases –Cells in Series Increase Voltage Parallel –2 or more Paths for e- –Add Resistors then Current Increases –Cells in Parallel Longer Battery Life

Alternating Current One side of the outlet would change from cheese to cat 60 times a second. Electrons move back and forth Produced by Power Plants _ _ + _ _ _ _ _ _ + _ _ + 120v

Direct Current Electrons move in one direction From negative to positive Produced by Batteries __ _ _ _ __ _ _ _ _ _ + +

Electricity The battery goes "dead" when all the negative charges make it through the circuit and get to the positive charges. _ _ _ _ _ _ _ _

Electromagnet Moving e- produce a magnetic field –More coils / More strength

Electromagnet Moving e- produce a magnetic field –More coils / More strength –More current / More strength

Generators Electromagnetic Induction – moving an coil of wire through a magnetic field

Generator Changes Mechanical Energy to Electrical Energy

Motor AC (alternating current) causes magnetic poles to flip making the armature spin

Motor Changes Electrical Energy To Mechanical Energy