Electricity
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Electricity requires moving electrons
• A difference in potential energy causes
charges to flow.
• Electrons flow from places of higher potential
energy to places of lower potential energy.
• Potential energy is measured in Volts “V”
Current
• A flow of charge is called a current
• Electric current is the amount of charge that
passes a given point per unit of time
• Use “I” to stand for current
What makes the electric charges
move?
• A device that uses some form of energy to
move the charges.
Ex. Battery
Electric generator
photo cell
Battery
A battery is a device that produces electricity
by converting chemical energy into electrical energy
So which way would the electrons
move from the battery if we were
to attach a wire?
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Circuits
• Circuit = a closed path through which
electrons can flow (current).
• Electrons flow in a circuit as long as there is a
potential difference and an unbroken path
Types of Circuits
A. Series circuit – a circuit with one path for the
electrons to flow.
B. Parallel circuit – a circuit with two or more
pathways
Household circuits
• Two wires run parallel (potential difference),
third wire is a ground (no current goes
through here)
Electrical Safety
• To much electricity = fire!!
• Due to heat build up
Fuses
• Thin strip of metal through which current
flows. If too much current, metal strip melts,
pathway is broken.
• Reset by changing fuse
Circuit breakers
• Use a switch that will flip open when current
is too high. Stops flow of current
• Reset by switching switch back to on.