Overhead power cables are used to transmit electrical power from a power station to a residential suburb located far away.
The transmission voltage of the cables is much higher than the generating voltage of the power station and the domestic mains voltage in the suburb.
Explain the scientific advantages of transmitting electrical power at a very high voltage.
A design engineer suggests that the energy loss can be further reduced by tripling the diameter of the copper cables.
Explain the effect of tripling the diameter on the total electrical resistance of the cables.
Suggest one practical disadvantage of tripling the diameter of the cables.
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.