A copper wire has resistivity 1.7 × 10⁻⁸ Ω m, length 2.0 m and cross-sectional area 1.0 × 10⁻⁶ m². Compute its resistance in mΩ, to the nearest whole number.

Physics II / Steady Currents and Circuits

Practice question · Numerical answer

A copper wire has resistivity $1.7 \times 10^{-8}$ Ω m, length 2.0 m and cross-sectional area $1.0 \times 10^{-6}$ m $^2$ . Compute its resistance in mΩ, to the nearest whole number.

Hints

Resistance is resistivity times length over area.
Compute 1.7e-8 x 2.0 / 1.0e-6.

Show the answer

34 (answers within ±1 count)

Why

$R = \rho L/A = 1.7 \times 10^{-8} \times 2.0/10^{-6} = 3.4 \times 10^{-2}\ \Omega = 34$ mΩ. Copper’s tiny resistivity is why household wiring can be thin and still lossless enough.

Read the lesson: Steady Currents and Circuits →

Practise Steady Currents and Circuits

The app has 6 more questions on this lesson, and keeps your place in the course. Physics II is free to start.

Start Physics II free Get it onGoogle Play

A copper wire has resistivity 1.7×10−81.7 \times 10^{-8}1.7×10−8 Ω m, length 2.0 m and cross-sectional area 1.0×10−61.0 \times 10^{-6}1.0×10−6 m2^22. Compute its resistance in mΩ, to the nearest whole number.

Practise Steady Currents and Circuits

More questions on Steady Currents and Circuits

A copper wire has resistivity $1.7 \times 10^{-8}$ Ω m, length 2.0 m and cross-sectional area $1.0 \times 10^{-6}$ m $^2$ . Compute its resistance in mΩ, to the nearest whole number.