$($c$)$ A current of $2$A is passed through a metal strip of width $(0\mathrm{.}01$ m $)$ and thickness $(0\mathrm{.}005$ m $).$ A magnetic field of $0\mathrm{.}5$ T is applied perpendicular to the current. The Hall voltage is measured to be $V_H=5{10}^{-4}.$ Calculate the Hall electric field $E_H$ across the strip and also determine the carrier concentration in the material.

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