Electrical power P P\,P is transmitted from a power station to a town at a high voltage V V\,V through cables of total resistance RRR.
Which expression correctly represents the rate of thermal energy loss (power loss) in the transmission cables?
Ploss=V2RP_{\text{loss}} = \frac{V^2}{R}Ploss=RV2
Ploss=P2RV2P_{\text{loss}} = \frac{P^2 R}{V^2}Ploss=V2P2R
Ploss=PRVP_{\text{loss}} = \frac{P R}{V}Ploss=VPR
Ploss=V2P2RP_{\text{loss}} = \frac{V^2}{P^2 R}Ploss=P2RV2
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.