P5: Electricity in the house 0.0 / 5 ? PhysicsAllGCSEAQA Created by: hannahh.hmCreated on: 13-08-17 18:51 A 40 W light bulb is switched on for 30 minutes. Calculate the energy it transfers. time taken = 1800 s. E = P x t. = 72,000 J 1 of 6 Calculate the normal current through a 500 W, 230 V heater. Current = 500 / 230 = 2.2 A. 2 of 6 Calculate the energy transferred in a component when the charge passing through it is 30 C and the potential difference is 20 V. E = V x Q. = 600 J. 3 of 6 A 230 V, 12 A electric motor in a machine has an efficiency of 60%. Calculate the electrical power supplied to it. power supplied = current x potential difference. = 2,760 W. 4 of 6 A 230 V, 12 A electric motor in a machine has an efficiency of 60%. Calculate the output power of the motor. efficiency as a ratio = 60% / 100% = 0.6 5 of 6 A 230 V, 12 A electric motor in a machine has an efficiency of 60%. Calculate the energy per second wasted by the motor. energy wasted per second = 2760 W - 1660 W = 1,100 W. 6 of 6

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