A high-precision heater element in a chemical reactor is connected to a 15.0 V d.c. power source. The current passing through the heating coil is 2.8 A during stable operation. Show that the total electrical energy transferred to the heater in 7.5 s is about 320 J.
31 exam-style questions on Edexcel GCSE Physics 10.3 Electrical energy and power. Each one has a worked solution and a mark scheme showing where the marks go.