Question

A current i, indicated by the crosses in figure, is established in a strip of copper of height h and width w. A uniform field of magnetic induction B is applied at right angle to the strip.
If the drift velocity $v_d$ of the electrons is $v_d=1.4\times {10}^{-x}m{s}^{-1}$. Find x.

Answer 1

The current density j is given by:
$j=\frac{i}{A}=\frac{50}{0.02\times 1.0\times {10}^{-2}}=25\times {10}^{5}A{m}^{-2}$

The drift velocity $v_d$ is given by:
$v_d=\frac{j}{ne}=\frac{25\times {10}^5}{1.1\times {10}^{29}\times 1.6\times {10}^{-19}}=1.4\times {10}^{-4}m{s}^{-1}$

This velocity will be in outward direction.