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Question
The resistance of filament of an electric heater is 500 Ω It is operated at 200V for 1 hour daily. Calculate the current drawn by the heater and the energy consumed in joule.
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Solution
Given: R= 500 Ω, V = 200 volt.
Total time = t = 1 × 30h = 30h = 30 × 60 = 60 s = 108000s.
Current drawn by the heater I = `"V"/"R" = 200/500 = 0.4` A
The energy consumed (in joule) = `"V"^2/"R" "t"`
`= (200)^2/500 xx 108000`
= 8640000 J.
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