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प्रश्न
A light bulb is rated at 125 W for a 250 V a.c. supply. Calculate the resistance of the bulb.
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उत्तर
Power of the bulb, P = 125 W, Voltage, V = 250 V
The resistance of the bulb is given as `R = V^2/P = 250^2/125 = 500 Ω`
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