A kettle requires 2400 Coulombs of charge to pass through its heating element, with a resistance of 6 Ohms, in a time of 200 seconds in order to boil the water inside it. Calculate the current flowing and the power of the kettle.
I=Q/t=2400/200=12AP=IV=I^2R=12^2*6=864W
Of course, when discussing the answer with a student I would verbally explain each step in detail and add more drawings to my workings. Unfortunately, I cannot do this by typing on a computer but am happy to talk you through this in the interview.
SL