If a student uses an electric kettle connected to a 230V mains power supply, with a heating power of 1.8kW. Assuming negligable losses, answer the following: a) find the current in the kettle b) find the total energy transferred in 2 minutes of operation
a) The governing equation here is Power = current x voltage or P=IV. using this formula, 1,800 = I x 230 => I=1800/230 = 7.83 A (3sf) b) as watts is equal to joules/seconds, we can find the energy in joules by multiplying the power by the time of operation in seconds, this would be 120 seconds for 2 minutes. Therefore the total energy used is 1,800*120 = 216,000J
CP
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