Equal potentials are applied on an iron and copper wire of same length.  In order to have
Channel: Doubtnut
Date: 2020-08-30

Equal potentials are applied on an iron and copper wire of same length.  In order to have the same current flow in the two wires, the ratio r (iron)/r(copper) of their radii must be (Given that specific resistance of iron `=1.0 xx 10^(-7) ohm-m` and specific resistance of copper `=1.7 xx 10^(-8) ohm-m`)