question_answer

If \[n,\,e,\,\tau \] and m respectively represent the density, charge relaxation time and mass of the electron, then the resistance of a wire of length \[l\] and area of cross-section \[A\] will be [CPMT 1992]

A)                    \[\frac{ml}{n{{e}^{2}}\tau A}\]

B)                                      \[\frac{m{{\tau }^{2}}A}{n{{e}^{2}}l}\]

C)                    \[\frac{n{{e}^{2}}\tau A}{2ml}\]

D)                                      \[\frac{n{{e}^{2}}A}{2m\tau l}\]