A copper wire of length 2.0 m and cross‑sectional area $1.0\times 10^{-6}{\text{m}}^2$ has a resistivity of $1.68\times 10^{-8}\Omega \text{m}$. Calculate its resistance.

Step-by-step solution

1. Write the formula $R=\rho \frac{L}{A}$ where $\rho$ is resistivity, $L$ length, $A$ area.
2. Substitute $\rho =1.68\times 10^{-8}\Omega \text{m}$, $L=2.0\text{m}$, $A=1.0\times 10^{-6}{\text{m}}^2$.
3. Calculate $\frac{L}{A}=\frac{2.0}{1.0\times 10^{-6}}=2.0\times 10^6$.
4. Multiply: $R=1.68\times 10^{-8}\times 2.0\times 10^6=3.36\times 10^{-2}\Omega$.
5. Write the result as $0.034\Omega$.

Concept tested: Resistance using resistivity formula

Published 21 August 2026 · How this solution was prepared and checked

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