Question

When 5 V potential difference is applied across a wire of length 0.1 m, the drift speed of electrons is $2.5\times {10}^{-4}$ m/s. If the electron density in the wire is $8\times {10}^{28}{m}^{-3}$, calculate the resistivity of the material of the wire.

Answer 1

Resistivity of a material is given by ,

$\rho =\frac{V}{v_{d}nel}$

Given: $V=5V,L=0.1m,v_d=2.5\times {10}^{-4}m/s,n=8\times {10}^{28}{m}^{-3}$

therefore $\rho =\frac{5}{2.5\times {10}^{-4}\times 8\times {10}^{28}\times 1.6\times {10}^{-19}\times 0.1}=1.56\times {10}^{-5}\Omega m$