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The apparatus for measuring the Hall effect is shown above. Consider a charge carrier $q$ (to keep you from having to mess with the negative charge on the real charge carriers - electrons) moving through the apparatus in a material with an unknown $n$ charge carriers per unit volume. Derive an expression for $n$, given $I$, $V_H$, $t$, $B$, $w$ and $q$. Note that I'd have to consider you moderately insane to have memorized this result (I certainly haven't) but by considering the strip to be a region of self-maintaining crossed fields and relating the current to the drift velocity you should be able to get it fairly easily.


Robert G. Brown 2003-02-09