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.)
(a) Find the total power delivered to the three bulbs. W
(b) Find the potential difference across each light bulb.
deltaVR1 = V
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.