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Question
An electric appliance is rated at 1000 W, 250V. Calculate:
(i) The electrical energy consumed by the appliance in 12 hour.
(ii) The cost of energy consumed at Rs. 1.20 per kWh.
How long would this appliance take to use 1 kWh energy when operated at 250 V?
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Solution
Given: P = 1000W, V = 250V, t = 12 hr
(i) Electrical energy consumed = `"Watt"/1000 xx "time" ("in hr.")`
`= 1000/1000 xx 12` = 12 kWh
(ii) Cost = 12 × 1.20 = Rs. 14.40
If it takes t hour to consume 1 kWh electric energy, then:
I = `(1000xx"t")/1000`
or t = 1 hr.
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