Download Electric Circuits - Mother Teresa Regional School

Section 4
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Ohm’s law: The resistance is equal to the
voltage divided by the current.
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Resistance= Voltage
Current
You can use this formula to see how changes in
resistance, voltage, and current are related.
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Circuits have devices that are run by electrical energy.
 These devices transform electrical energy into
another form of energy. Example: Light bulb
transforms electrical energy into electromagnetic and
gives off light.
 Light bulbs and fans are resistors because they resist
the flow of electric current.
A circuit has a source of electrical energy.
 Batteries, generators, and electric plants are sources
of electricity.
Electric Circuits are connected by conducting wires.
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The conducting wires complete the path of the current and
allow charges to flow from the energy source to the device.
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In a series circuit, there is one path of energy
for the current to take.
The part are connected one after another.
Very simple to design and build
What happens if one bulb in series burns out?
Why?
Resistor: the more light bulbs you add to a
series circuit, the dimmer the light bulbs will
be.
Ammeter: Device used to measure current.
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Parallel Circuits provide several paths for the
flow of electrons.
Each bulb is connected by a separate path from
the battery.
If one bulb burns out, the others will be able to
stay lit.
Resistance decreases in a parallel circuit.
A voltmeter is a device used to measure
voltage or electrical potential energy difference.