Two copper wires P and Q are made of the same material and kept at the same temperature
PHYSICS · Multi-part · AP · Physics 2: Algebra-based · Electric Circuits · Electric Circuits
Problem
Two copper wires P and Q are made of the same material and kept at the same temperature. Wire Q is twice as long as wire P but its radius is half that of P.
(i) Which of the two wires has the greater resistance? Justify your answer without using numerical values.
(ii) Compare the resistivities of the two wires and give a reason for your conclusion.
(iii) If both wires are heated so that their temperatures rise by the same amount, explain qualitatively how their resistances will be affected. State why the resistivity, and not the dimensions, governs this temperature behaviour.