Question

12. Find the potential drop along a copper wire 500 m long and 2 mm in diameter if the current in it is equal to 2 A

Answer 1

Solution

Length of wire l=500m

Radius R=1mm

So area $A=\pi r^2=3.14\times1mm\times1mm$

$A=3.14\times10^{-6}m^2$

Resistivity of copper wire

$\rho=1.68 * 10^{-8} Ω -m$

So potential difference of wire

$V=IR\\=\frac{I\rho l}{A}$

Putting all values

$V=\frac{2\times1.68 * 10^{-8}\times500 }{3.14\times10^{-6}}\\=5.35Volts$