Download Getting A Charge Out of Electricity

Getting A Charge Out of
Electricity
Compare Chapter 2 Section 2.2
How Much Juice is On the Loose?

Electricity is electrons moving along



Little juice particles moving along the
line
The flow of electrons in an electric
Circuit is called the current (T4A03)
We Measure the amount of current
flow in Amperes (T4A01)
We often just call them Amps
 Big numbers mean more juice is moving
than little numbers


We measure the flow of current in
an electric circuit with an Ammeter
(T4A12)
How Hard Does the Electricity Punch

The strength of electricity’s punch is
called its Electromotive Force (EMF)


Electromotive Force is measured in
Volts
You measure Electromotive Force –
such as between battery terminals with
a Voltmeter (T4A13)
Power – Watt hit Me?



Power is the number of punches
amps (current) * how hard you got
punched (voltage)
Electrical Power is Measured in
Watts (T4A02)
The Unit Used to Describe
Electrical Power is the Watt (T4E01)
Ohm My!

Always resistance to flow of current


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The Basic Unit of Resistance is the Ohm (T4A07)
The Opposition to flow of current is called
Resistance (T4A11)


If little kid tries to hold the door closed won’t be
much resistance
If Hulk Hogan tries to hold the door closed likely will
be a lot of resistance
The more ohms the more resistance
Some things have low resistance and conduct
electricity well

Copper is an example of a good conductor

Glass is an example of a good insulator
(T4A09)
(T4A10)
Formulas Voltage and Power
Ohms Law Relationship
P
E
I
R
E = Volts
I = Current or Amperes
R = Resistance
E
E=IxR
I = E/R
R = E/I
I
P =Power P = E x I
E = Volts E = P/I
I = Amps I = P/E