Two exactly similar electric lamps are arranged (i) in parallel, and (ii) in series. If the parallel and series combination of lamps are connected to 220 V supply line one by one, what will be the ratio of electric power consumed by them?

As we know that

Electric power consumed = V2/R


Here V is given we have to find the value of R


So when the connection is in parallel


The equivalent resistance is



Electric power consumed in parallel connection



When the connection is in Series


The equivalent resistance = R+R = 2R


Electric power consumed in series connection



The ratio of electric power consumed by them



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