Question

Calculate the area of cross-section of a wire if its length is 1.0 m, its resistance is 23 Ω and the resistivity of the material of the wire is 1.84 × 10⁻⁶ Ω m.

Answer 1

Length of the wire, l =1.0 m

Resistance of the wire = 23 Ω

Resistivity of the material of the wire = 1.84 × 10⁻⁶ Ωm.
We know that,
$R=\frac{\mathrm{\rho }l}{A}$

Area of cross-section,

$A=\frac{1.84\times {10}^{-6}\times 1}{23}$

A = 8 x 10^-8 m²

Thus, the area the of cross-section of the wire, A = 8 x 10^-8 m²