PHYSICS · Single correct · A Level · Physics · Electricity · Electricity
Problem
Two copper wires A and B have the same length. The radius of A is r while that of B is 2r. Each wire is connected separately across the same ideal battery of emf V. What is the ratio of the power dissipated in wire B to that in wire A?
(a) 1:4
(b) 1:2
(c) 4:1
(d) 2:1