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Why does a 60W bulb glow brighter than a 100W bulb in a series?

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up vote 1 down vote favorite 2 In my physics class I have this problem that shows two lightbulbs, one 60W and one 100W in series, connected to a 120V battery. The problems are: Which bulb is brighter? (A: 60W) Calculate the power dissipated by the 60W bulb. (A: 23.4W) Calculate the power dissipated by the 100W bulb. (A: 14.1W) Why is the power dissipated not simply the wattages of the bulbs? I followed one workthrough online where you first find R for both using P = (V^2)/R and then use I = V/R to get a current of 0.3125A. The power dissipated is then calculated using P = I^2R and you get the above answers. However, doesn't that assume the voltage drop between the lightbulbs is 120V in both cases, and isn't that wrong? I tried getting it another way where I said P1 = IV1, P2 = IV2, and V1+V2=120(Volts). I solved t...