Question

A current of $5A$ passes through a copper conductor $(resistivity=1.7\times {10}^{-8}\Omega m$) of radius of cross-section $5mm$. Find the mobility of the charges if their drift velocity is $1.1\times {10}^{-3}m/s$

• A. $1.3m^2/Vs$
• B. $1.5m^2/Vs$
• C. $1.8m^2/Vs$
• D. $1.0m^2/Vs$

Answer 1

The correct option is D $1.0m^2/Vs$

$\mu =\frac{V_d}{E}$ $E=\rho J$

$=\frac{1.1\times {10}^{-3}}{1.7\times {10}^{-8}\times \frac{5}{\pi \times 25\times {10}^{-6}}}$

$=\frac{1.1\times {10}^{-3}\times \pi \times 25\times {10}^{-6}}{1.7\times {10}^{-8}\times 5}\approx 1.01m^2/Vs$