Question

what is the resistance of a 30 m silver wire with a 2 mm diameter

Answer 1

Length of silver wire = 30 m

Diameter of silver wire is = 2mm =2×10^-3

area of cross section of wire = $\pi r^2= 3.14×(2×10^{-3})^2$

A=12.56×10^-6

Resistivity of silver wire = 1.59×10^-8

$R=\frac{\rho l}{A}$

$R=\frac{1.59×10^{-8}× 30}{12.56×10^{-8}}$

R= 3.797 $\Omega$