A loudspeaker needs a household voltage of 110 V to push a current of 5 A through its coil. What is the resistance of the loudspeaker?
A loudspeaker needs a household voltage of 110 V to push a current of 5 A through its coil. What is the resistance of the loudspeaker?
I assume that we're going to neglect the complexities of calculating alternating current versus direct current, and simply go with the standard formula of E = IR. Voltage = Current x Resistance They use E for voltage because it stands for Electromotive Force, but I don't know why they use I to represent current, maybe it's from Latin or something like that. We're also going to neglect the inconvenient fact that it requires a varying direct current to drive a speaker.
E = IR
Since we're looking for resistance,
we want to isolate R on one side of
the equation, so divide both sides by I R = E / I
Plug in the known values R = 110 / 5
R = 5 Ω
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