Power is expressed as:
Therefore, R = V2/P
For the 30W bulb, R30 = (120)2/30 = 480Ω
For 60W bulb, R60 = (120)2/60 = 240Ω
Curent, i = V/R
Two light bulbs use 30 W and 60 W, respectively, when connected in parallel to a 120-V source.
How much power does each bulb use when connected in series across the 120-V source, assuming that their resistances remain the same?
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