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Question
How much energy is consumed when a current of 5 amperes flows through the filament (or element) of a heater having resistance of 100 ohms for two hours? Express it in joules.
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Solution
Given:
I = 5 A
R = 100 Î
Power consumed, P= I2R
= (5)2 100 watt
= 2500 watts=2.5 kW
Energy consumed, E = P x time
= 2.5 x 2
= 5 kWh
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