Can you unscramble the
terms?
SGARCHE
EGATOVL
EERPAM
EIRW
Describe what makes this electric
sign light up when it is in use.
What is happening when we ‘plug’
something in?
● moving charges provide electrical energy to
power the …..lamp, TV, XBOX, car, etc.
The rate of flow of electrical charges
is called Electric Current
Think of electric current
like people walking
through turnstiles…..If we
counted the number of
people going through the
turnstile in one minute, it
would be the RATE of
flow of people
With electric current… we measure
the amount of charge that passes a
point in the wire every second
unit for electric current= Amperes (amps) (A)
Two kinds of current
Direct Current (DC)
Alternating Current (AC)
● charges flow in same
direction
● flow one way, then the other
(alternating direction)
●
ex: batteries
● ex: outlets
So you know how opposites attract?
Well, this ‘opposites attract’ thing is what drives
the electric current
Like charges repel
Opposites charges attract
This attraction creates the
voltage
Voltage:
the difference in electrical potential energy between 2 places
age
Lo
w
Volt
ge
lta
Vo
Vo
lta
ium
ge
Med
h
ig
H
A lot of attraction
between the positive and
negative charges, so
there is a lot of electrical
potential energy
No
V
a
olt
ge
No attraction between
the negative and
negative charges, so
there is no electrical
potential energy
I found one……..
click
here
for
some
music
Is there something in this song that makes
you go “hmmmm”??? If so, let me know!
Fun fact: the band's name comes
from the sister of band members
Malcolm and Angus Young, who
saw the initials on a sewing
machine. To the band, it
symbolizes the “raw power” of their
music.
creates a potential difference in an electric circuit
Generators
Batteries
Resistance
How difficult it is
for charges to flow
through a material
Greater resistance = less
current
Factors that determine resistance
Material (conductors or insulators)
Length (longer = more resistance)
Diameter (thin wire = more resistance)
Temperature (higher temp = more resistance
Check out this Phet Simulation to ‘see’
Resistance
What happens to Resistance (R) as you increase the length (L in cm) of the wire?
What happens the Resistance as you increase the diameter of the wire?
(for the equation in the simulation, they use area (A in cm2)
Watch This for
Review