An electric heater is connected to a 240 V supply, and there is a current of 15 A in the heater. It takes 15 minutes15\text{ minutes}15 minutes to warm a room to the required temperature.
How much energy is supplied by the heater?
3.6×103 J3.6 \times 10^3\text{ J}3.6×103 J
5.4×104 J5.4 \times 10^4\text{ J}5.4×104 J
1.6×105 J1.6 \times 10^5\text{ J}1.6×105 J
3.2×106 J3.2 \times 10^6\text{ J}3.2×106 J
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.