Chhattisgarh PMT Chhattisgarh PMT Solved Paper-2007

  • question_answer
    Ratio of resistance of two bulbs 40 W and 60 W connected across 220 V source is

    A)  3:2                                        

    B)  3:8

    C)  4:3                                        

    D)  9:4

    Correct Answer: A

    Solution :

    Power of a bulb \[(P)=\frac{{{V}^{2}}}{R}\] \[\therefore \]  \[R=\frac{{{V}^{2}}}{P}\] \[\therefore \]  \[\frac{{{R}_{1}}}{{{R}_{2}}}=\frac{{{P}_{2}}}{{{P}_{1}}}=\frac{60}{40}=\frac{3}{2}\]


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