WAEC Physics 2011 Paper

Concept:Power loss in transmission lines depends on current squared: $P_{\text{loss}} = I^2R$.Explanation:To transmit a fixed power, the relation is $P = VI$.If voltage $V$ is low, the current $I$ must be high to send the same power.This high current increases heating loss in the cables because $P_{\text{loss}} = I^2R$.Hence, transmitting at low voltage and high current causes significant power losses.Large-diameter cables reduce resistance $R$, and high voltage with low current reduces $I$, so those options reduce losses.Answer:C. transmitting at relatively low voltage and high current