You have a piece of copper with a volume of 2 cm3, and wish to form a wire having a resistance of

Question

0.15 ƒ¶. How long should the wire be if the resistivity of copper is 1.72 �~ 10-8 ƒ¶. m?

Answer 1

V=A•L
A=V/L
R=ρL/A = ρL²/V
L=sqrt{RV/ρ} =
=sqrt{ 0.15•2•10⁻⁶/1.72•10⁻⁸} = 4.17 m