Transcript What property of electric current allowed Edison*s first light bulb to

What property of electric
current allowed Edison’s first
light bulb to light?
Electric Current
Electric current – The net movement of
electric charges in a single direction
through a wire or conductor.
Voltage difference – The force that causes
electric charges to flow; charges flow
from high voltage to low voltage.
Circuit – A closed path
that electric current
follows
Circuits include a power
source (battery), wires,
and some resistor (light
bulb) and a voltage
difference allows
current to flow.
Batteries
Dry Cell
 Chemical reactions
occur in a moist
paste causing the
transfer of
electrons
 Ex. AA or D battery
Wet Cell
• Contains two
connected plates
made of different
metals in
conducting
solution.
• Ex. Car battery
Resistance – The tendency for a material to
oppose the flow of electrons, changing
electrical energy into thermal and/or
light energy.
Ex. Light bulb, dial, switch, heating coil
Making wires thinner, longer, or hotter
increases resistance.
All materials have some electrical resistance
measured in ohms (Ω).
Ohm’s Law – current in a circuit equals voltage
difference divided by the resistance.
Current (I) = voltage difference (V)
resistance (R )
Current measured in amps (A), voltage difference
measured in volts (V), resistance measured in
ohms (Ω)