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pstir2
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Homework Statement
In America power is supplied at 110 V. In Australia power is supplied at 240 V, however American lights are routinely used in Australia.
a) How is this possible?
b) Calculate the power that a pair of 1000 W 110 V light would dissipate when plugged into a 240 V system in series.
c) Calculate the power that a 1000 W 110 V light would be required to dissipate when plugged directly into a 240 V system.
Homework Equations
V=IR
P=VI
P=(V^2)/R
P=(I^2)V
Total Resistance = R1 + R2 + R3 + ... + Rn
The Attempt at a Solution
I'm not sure if this is correct or even going in the right direction.
A) I'm not sure. I am not great at the conceptual side of this subject.
B)
Resistance of one bulb
P=(V^2)/R
1000=(110^2)/R
R=12.1
Total Resistance = R1 + R2
=12.1+12.1
=24.2
Power from outlet
P=(V^2)/R
P=(240^2)/24.2
P=2380.17W
Power Dissipated = 2380.17-2000
=380.17W
The two lightbulbs in series would need to dissipate 380.17 Watts of power.
C)
P=VI
1000=110I
I=9.09A
P=VI
P=240x9.09
P=2181.81W
Dissipated Power = 2181.81-1000
= 1181.81W
The lightbulb would need to dissipate 1181.81 Watts of power.
Alternate Answer to 'C'
Resistance of one bulb
P=(V^2)/R
1000=(110^2)/R
R=12.1
Power from outlet
P=(V^2)/R
P=(240^2)/12.1
P=4760.33W
Power Dissipated = 4760.33-1000
=3760.33W
The lightbulb would need to dissipate 3760.33 Watts of power.
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