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Hey guys,
I'm doing electrical theory and i stumbled on a question as follows:
A 120v, 100w heater is connected to 208v, what is the output of the heater?
Frankly, i dont get it. I know how to calculate it when given the power the heater receives, but only if efficiency is involved:
Pout=E*I >> n=out/in, given at least 3 variables.
Here though, it doesnt make sense. I already see that the heater is rated at 120v and 100w, there is no mention of current anywhere, and subbing the 208 for 120 isnt correct because that just calculates a new current value.
Any idea what to do?
>>
120v * ??? = 100w
208v * ??? = ...
>>
>>274643
see, I get that. But solving for ??? would give you a current value unique to that set of V and P. Are we assuming that after I solve for current, I use that same value to calculate the new P? That doesn't seem right - why would the current of the bulb stay the same if I apply more voltage?
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