(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

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 =

2. Relevant equations

I^2R = P

DeltaV = IR

DeltaV/I = R

p/v = I

3. The attempt at a solution

The first thing I did was find the current which is80/135 = .5925. From this I found the resistance which is135/.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.

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# Homework Help: Circuit (need help badly)

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