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Question
An electric iron is rated at 230 V, 750 W. What is its resistance? What maximum current can be passed through it?
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Solution
V = 230 V, Power = 750 W
P = V × I
∴ 750 = 230 × I
∴ I = 750/230
∴ I = 3.26 A
By Ohm's law `"V"/"I" = "R"`
∴ R = `230/3.26`
∴ R = 70.53 Ω
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