Electric EnergyElectric Energy

The energy of electrical chargesThe energy of electrical charges In order for charges to move, an electric In order for charges to move, an electric

field (area where another object field (area where another object experiences a force) must be set up and experiences a force) must be set up and start the electrons movingstart the electrons moving

Voltage:Voltage:

How much work is needed to move a How much work is needed to move a charge between 2 pointscharge between 2 points

The higher the voltage, the more The higher the voltage, the more electricity is released per chargeelectricity is released per charge

The potential difference between two The potential difference between two points that cause charges to movepoints that cause charges to move Measured in volts (V)Measured in volts (V)

Current:Current:

- The flow of charges,- The flow of charges,

- The rate at which charges pass - The rate at which charges pass through a pointthrough a point

- Measured in amperes (A)- Measured in amperes (A)

Voltage & Electrical Voltage & Electrical CurrentCurrent

As long as there is a voltage between 2 As long as there is a voltage between 2 points on a wire, charges will flow points on a wire, charges will flow through the wirethrough the wire

The greater the voltage, the greater the The greater the voltage, the greater the currentcurrent

2 Types of current in 2 Types of current in electrical energyelectrical energy

DirectDirect AlternatingAlternating

Direct currentDirect current

Charges flow in the same directionCharges flow in the same direction Example: batteriesExample: batteries

Indirect currentIndirect current

Charges shift flow from one direction to anotherCharges shift flow from one direction to another Advantage is that the voltage can change between the electrical Advantage is that the voltage can change between the electrical

producer & the userproducer & the user 22,000 V to 120 V22,000 V to 120 V

ResistanceResistance

A factor that that determines the amount of A factor that that determines the amount of current in a wirecurrent in a wire

The opposition to the flow of electric charge; The opposition to the flow of electric charge; “electrical friction”“electrical friction”

Depends on Depends on Material -Good conductors have low resistanceMaterial -Good conductors have low resistance

Thickness – thicker, less resistanceThickness – thicker, less resistance Length – shorter, less resistanceLength – shorter, less resistance Temperature- hotter, more resistance due to Temperature- hotter, more resistance due to

vibrationvibration

Ways that electricity can Ways that electricity can be generatedbe generated

Generators – ME to electricalGenerators – ME to electrical Cells –chemical & radiant to electricalCells –chemical & radiant to electrical Thermocouples –thermal to electricalThermocouples –thermal to electrical Photocells – light energy to electricalPhotocells – light energy to electrical

CellsCells

Cells change chemical or radiant energy Cells change chemical or radiant energy into electrical energyinto electrical energy

Wet and dry cell batteriesWet and dry cell batteries

http://www.ndt-ed.org/http://www.ndt-ed.org/EducationResources/HighSchool/EducationResources/HighSchool/Electricity/alternatingcurrent.htmElectricity/alternatingcurrent.htm

http://videos.howstuffworks.com/hsw/http://videos.howstuffworks.com/hsw/13373-understanding-electricity-how-13373-understanding-electricity-how-electricity-works-video.htmelectricity-works-video.htm