Electricity

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Electricity
Created By Mr. Mossey
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Electric Charge

• A property of Electrons and Protons.

Electrons Negative Charge (-)
Protons Positive Charge ()
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Charge Interactions

• Like Charges Repel

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• Opposite Charges Attract

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Electric Fields

• The force an electric charge exerts over a
  distance.

Multiple charges field interacts based on
rules of opposites attract and likes repel.
Single charge field radiates in all directions.
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Static Charge
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• Atoms are usually neutral (same numbers of
  protons and electrons).

Objects can become charged if
OR
Electron joins an atom negative charge
Electron leaves atom positive charge
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Transferring Charge

• Charge can be transferred in three ways.

Electrons always move
Conduction
Induction
Friction
Charged by Field Interaction
Charged by Direct Contact
Charged by Rubbing
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Static Discharge

• The loss of static electricity.

Objects want to become neutral
So if negative and positive come in contact, they
interact.
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Electric Current

• The flow of charge through a material.

Unit of Current Ampere
Ampere the amount of charge that passes through
a wire in a given time. (rate of current flow)
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Type of Current
Direct Current
Alternating Current
Current flows in one direction
Current repeatedly reverses direction
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Potential Energy

• The energy of position.

Energy flows from
? High potential energy
Electrical Potential the potential energy per
unit of electric charge.
To low potential energy ?
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Potential Difference

• The difference in electric potential between
  two places. (Called Voltage Unit Volts)

• As long as there is a potential difference
  current will flow.

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Voltage Sources

• Creates and maintains a potential difference
  (voltage) between two points.

Increased voltage Increased electric current
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Voltage vs. Current
Current numbers of electrons
Voltage load of each electron
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Resistance
Thickness thinner more
Length longer more

• Opposition to flow of current. (unit Ohm ?)

e -
Greater resistance Less current flow
Material insulator more
Temperature higher more
Depends on
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Ohms Law

• Relates resistance to voltage and current.

Resistance Voltage/ Current
Words
R V/I
Symbols
Ohms Volts/ Amps
Units
All three say the same thing
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Ohms Law

• Do word problems the same way as density.

You light a light bulb with a 1.5 volt battery.
If the bulb has a resistance of 10 ohms, how much
current is flowing?
Use your triangle
R 10 ohms I ? V 1.5 volts
Know
SO
I V/R
Solve
I 1.5 / 10
Answer
0.1 Amps
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Electric Circuits

• Complete path through which electric charge can
  flow.

Closed Circuit
Open Circuit
e-
? Electrons can not flow
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Types of Circuits
Parallel Circuit several paths for electrons to
flow
Series Circuit only one path for electrons to
flow
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More lights No dimming
More lights Grows dimmer
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THE END