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प्रश्न
An electric kettle is rated 2.5 kW, 250 V. Find the cost of running the kettle for two hours at Rs. 5.40 per unit.
उत्तर
Given ,
Power of kettle , P = 2.5 kW
Voltage , V = 250 V
Time, t = 2 h
As , Energy , E = P × t
= 2.5 × 2 = 5 kWh
Cost per unit of energy = Rs 5.40
Cost for 5 kWh of energy = 5.40 × 5 = Rs 27
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