Resistors and Ohm's Law Video Lessons

Concept

# Problem: In household wiring, copper wire 2.05 mm in diameter (12 gauge) is often used. Find the resistance of a 24.0 m length of this wire. Note the resistivity of copper is 1.72×10-8 Ω·m.

###### FREE Expert Solution

Resistance:

$\overline{){\mathbf{R}}{\mathbf{=}}\frac{\mathbf{\rho }\mathbf{l}}{\mathbf{A}}}$

where ρ is the resistivity, l is the length, and A is the area.

A = π(d/2)2 = π(2.05mm/2)2(1m/1000mm)2

85% (397 ratings)
###### Problem Details

In household wiring, copper wire 2.05 mm in diameter (12 gauge) is often used. Find the resistance of a 24.0 m length of this wire. Note the resistivity of copper is 1.72×10-8 Ω·m.