Question

Calculate the resistance of an aluminium wire of length $50\text{cm}$ and cross-sectional area $2.0{\text{mm}}^2$. The resistivity of aluminium is $2.6\times {10}^{-8}\Omega \text{m}$.

• A. $0.0065\Omega$
• B. $0.065\Omega$
• C. $0.65\Omega$
• D. $6.5\Omega$

Answer 1

The correct option is A $0.0065\Omega$

We know that, resistance,
$R=\rho \frac{l}{A}$

$\Rightarrow R=2.6\times {10}^{-8}\times \frac{50\times {10}^{-2}}{2.0\times {10}^{-6}}$

$\Rightarrow R=0.0065\Omega$