Q15 of 31 Page 252

Two bulbs have ratings 100 W, 220V and 60 W. 220 V. Which one has the greater resistance?

We know P = V2/R

So R = V2/P


First bulb


R = = 484 ohm


Second bulb


R = = 806.66 ohm


So second bulb with 60 W, 220 V has greater resistance.


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