(a) How does the resistance of a wire depend on its radius? Explain your answer.
(b) Two copper wires are of same length, but one is thicker than the other. Which will have more resistance?
(a) The resistance of a wire is inversely proportional to the area of cross-section.
R∝1A
This is because in a conductor with a larger cross-section, electrons can flow easily and so the resistance is less.
(b) If length of both copper wires is the same, the thinner wire will have more resistance.