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Question
Find the cost of operating an electric toaster for two hours if it draws 8 A current on a 110 volt circuit. The cost of electrical energy is Rs. 2.50 per kWh.
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Solution
Time = 2 hrs, I = 8A, V = 110 volt
Power = IV
= 8 × 110 = 880 Watt
Electrical energy (in kWh) = `("Power"("in Watt") xx "Time"("in hour"))/1000`
`= (880 xx 2)/1000`
= 1.76 kWh
Cost of 1 kWh energy = Rs. 2.50
Cost of 1.76 kWh energy = 2.50 × 1.76
Rs. 4.40
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