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BunDa4Th
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Homework Statement
Three 80.0 W, 135 V lightbulbs are connected across a V = 135 V power source, as shown in Figure P18.48. (Assume that the resistance of each bulb is constant even though, in reality, the resistance increases markedly with current.)
http://www.webassign.net/sercp/p18-48alt.gif
(a) Find the total power delivered to the three bulbs. W
(b) Find the potential difference across each light bulb.
deltaVR1 = V
deltaVR2 =
deltaVR3 =
Homework Equations
I^2R = P
DeltaV = IR
DeltaV/I = R
p/v = I
The Attempt at a Solution
The first thing I did was find the current which is 80/135 = .5925. From this I found the resistance which is 135/.5925 = 227.85 ohm.
From there I tried using the formula I^2R= P, which gave me the incorrect answer. Then I thought since R2 and R3 are parallel I can combine it by using the formula 1/R = 1/R1 + 1/R2. But that got me a bit confuse and still gave me an incorrect answer.
I am not sure where to start and what steps I am doing wrong or missing. Any help would be great.