A high-power electric vehicle (EV) charger is connected to the domestic electrical power supply using insulated copper cables. During charging, the cables become significantly warm.
Which of the following changes would reduce the thermal energy (heat) generated in the cables?
Use copper cables with a larger cross-sectional area.
Use copper cables with a smaller cross-sectional area.
Use cables with thicker plastic insulation.
Use longer copper cables of the same cross-sectional area.
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.