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

Related Physics GCSE answers

All answers ▸

How does a radioactive nucleus emit electrons when it doesn't contain any?


A rock fragment weighing 50N is displaced from the top of a cliff and falls 0.12 km to the ground. Calculate the kinetic energy (in J) of the rock just before it hits the ground. Assume air resistance is negligible.


Explain Ohms Law


Using the kinetic molecular theory,explain why air pressure inside a syringe increases if the volume decreases from 15.0 cm