Electricity

1
Electricity
2
Electricity

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

3
Electricity

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

4
Electricity

• Negative charges have no mass
• and are free to move.
• Negative charges move through materials called
  conductors.

5
Electricity

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

6
Electricity
_

• Negative charges are attracted to positive
  charges
• like mice are attracted to cheese.

7
Static Electricity

• Build up of Electrons creating Electric Charge
• Created By
• Friction
• Induction
• Conduction
• Until you get

8
Static Discharge
9
Electricity
_

• Anytime there is a natural attraction between two
  things
• you 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).

10
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.

11
Electricity
_

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

12
Resistance

• Decrease
• Short wire
• Thick wire
• Cooler wire

• Increase
• Long wire
• Thin Wire
• Warm Wire

13
Electricity
_
_
_
_
_
_

• Current
• The number of charges (mice) passing a point
  per second.
• The rate of flow of charges.

14
Electricity
_
_
_
_



_
_



_
_

• D Battery
• 1.5 volts 15 amps

15
Electricity
_
_
_

_
_


_

_


_

• AA Battery
• 1.5 volts 2.8 amps

16
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.

17
Circuits

• Series
• One Path for e-

• Parallel
• 2 or more Paths for e-

18
Circuits

• Series
• One Path for e-
• Add Resistors thenCurrent Decreases

• Parallel
• 2 or more Paths for e-
• Add Resistors thenCurrent Increases

19
Circuits

• Series
• One Path for e-
• Add Resistors thenCurrent Decreases
• Cells in SeriesIncrease Voltage

• Parallel
• 2 or more Paths for e-
• Add Resistors thenCurrent Increases
• Cells in ParallelLonger Battery Life

20
Alternating Current
_
_
_



_


_
120v
_
_

• One side of the outlet would change from cheese
  to cat  60 times a second. 
• Electrons move back and forth
• Produced by Power Plants

21
Direct Current

• Electrons move in one direction
• From negative to positive
• Produced by Batteries

_
_

22
Electricity
_
_
_
_



_
_



_
_

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

23
Electromagnet

• Moving e- produce a magnetic field
• More coils / More strength

24
Electromagnet

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

25
Generators

• Electromagnetic Induction moving an coil of
  wire through a magnetic field

26
Generator

• Changes
• Mechanical Energy to
• Electrical Energy

27
Motor

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

28
Motor

• Changes
• Electrical Energy
• To
• Mechanical Energy