Answer
$V=7.4{\mu}V$
Work Step by Step
We know that,
$n=\frac{Bi}{Vle}$
We now re-arrange the above formula to find $V$:
$V=\frac{Bi}{nle}$
We plug in the known values to obtain:
$V=\frac{0.65\times 23}{8.47\times 10^{28}(150\times 10^{-6})(1.6\times 10^{-19})}$
$V=7.4\times 10^{-6}$
$V=7.4{\mu}$V
