Would all the bulbs of the same wattage change in brightness if one of them got

Question

Would all the bulbs of the same wattage change in brightness if one of them got taken away? I would say no because if you take a 3 or 4 way lamp and remove or shut down one of the bulbs, they would still remain the same. At least in my lamp it is this way. But, I have seen other appliances draw current and make my bulbs dimmer.
the problem is on pg. 205 problem 43 about three bulbs on the same current. I think the current to each bulb is the same in regards to the other 2. Can you explain this to me and direct me where I am wrong?

Explanation / Answer

This depends whether they are connected in parallel or series. If in series and say the resistance of each is R. then total resistance is 4R and if battery voltage is V, current is V/(4R). Also, each will get V/4 voltage across them. thus, power given off is V^2/4R. Now when we remove one, current becomes V/3R and voltage becomes V/3. Thus, power is V^2/9R. However, if in parallel, voltage across all will be V. and total resistance will be R/4. thus, current is 4V/R. but current in each branch of parallel circuit will be only 1/4th of that which is V/4. thus, power of each bulb is V^2/4. now if you remove one, voltage remains V across all but total current drops to 3V/R because resistance is R/3. however, current in each branch is V/R so power is same. in this case, brightness is not affected. let me know if you need more help:)

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