Question

An aluminium wire of diameter $0.24cm$ is connected in series to a copper wire of diameter $0.16cm.$ The wires carry an electric current of $10A.$ Determine the current density in aluminium wire.

Answer 1

Radius of aluminium wire=$1.25\times {10}^{-3}m$

Cross-sectional area of aluminium=$\pi r^2$

$=4.9\times {10}^{-6}m$

$\therefore J=\frac{10}{4.9\times {10}^{-6}}=2.04\times {10}^{6}A{m}^{-2}$