A homeowner accidentally leaves a 60 W floor lamp switched on when going to bed at 10:30 p.m. (22:30) one night. They do not discover this until they turn it off at 6:30 a.m. (06:30) the next morning.
The mains electricity supply is 240 V.
Calculate how much energy was wasted by the lamp.
Calculate the electric charge that passed through the lamp during this time.
What happened to the energy wasted by the lamp?
452 exam-style questions on CIE IGCSE Physics 4.2 Electrical quantities, covering 4.2.1a Positive and negative charge, 4.2.1b Charging by friction and detecting charge, 4.2.1c Electrical conductors and insulators, 4.2.1d Electric fields and electric field patterns, 4.2.2a Electric current, charge and measuring current, 4.2.2b Conduction in metals and the direction of current, 4.2.2c Direct current and alternating current, 4.2.3a Electromotive force, 4.2.3b Potential difference and voltmeters, 4.2.4a Resistance, 4.2.4b Resistance of a metallic wire, 4.2.4c Current–voltage graphs, and 4.2.5 Electrical energy and electrical power. Each one has a worked solution and a mark scheme showing where the marks go.