Question

    A 220 V, 100 W bulb is connected to a 110 V source. Calculate the power consumed by the bulb

    A 25 W Correct Answer Incorrect Answer
    B 20 W Correct Answer Incorrect Answer
    C 21 W Correct Answer Incorrect Answer
    D 27 W Correct Answer Incorrect Answer

    Solution

    Given - Potential difference (V) = 220 V, power of bulb (P) = 100 W and actual voltage (V') = 110 V => R = V2/P = (220)2/100 = 484Ω Therefore, the power consumed by the bulb => P = V2/R = (110)2/484 = 25 W

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