You are given three bulbs of 25 , W,40 , W,an | vedclass

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(A) The power rating of a bulb is given by the formula $P = \frac{V^2}{R}$,where $V$ is the voltage and $R$ is the resistance.From this formula,we can

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$60 \, W$ bulb

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(A) The power rating of a bulb is given by the formula $P = \frac{V^2}{R}$,where $V$ is the voltage and $R$ is the resistance.From this formula,we can express resistance as $R = \frac{V^2}{P}$.Since the voltage $V$ is constant $(220 \, V)$ for all three bulbs,the resistance $R$ is inversely proportional to the power $P$ $(R \propto \frac{1}{P})$.Therefore,the bulb with the highest power rating will have the lowest resistance.Comparing the given power ratings: $60 \, W > 40 \, W > 25 \, W$.Thus,the $60 \, W$ bulb has the lowest resistance.

You are given three bulbs of $25 \, W$,$40 \, W$,and $60 \, W$ marked at $220 \, V$. Which one of them has the lowest resistance?

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