A high-power electric vehicle charger is connected to the mains power supply using insulated copper wires. During charging, the wires become noticeably warm.
What modification to the connecting wires would reduce the rate at which thermal energy is generated in them?
Use copper wires with a larger cross-sectional area.
Use copper wires with a smaller cross-sectional area.
Use copper wires with a longer length.
Use wires with thicker outer insulation.
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.