Question

A 2-meter copper conductor which has a cross-sectional area of 8 x 10 – 7 m2 has a potential energy difference of 6 volts between its ends. The resistivity of copper is 1.7 x 10 – 8 Ω-m. Find:

a. The resistance of the conductor, and

b. The current passing through it

Answer 1

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

Where

R = is the resistance

$\rho$ = is the resistivity

L= is the length

A = is the cross sectional area

$R= 1.7×10^{-8}\Omega m[\frac{2m}{8×10^{-7}m^2}]$

$R=\frac{3.4×10^{-8}\Omega m^2}{8×10^{-7}m^2}$

$R= 0.0425\Omega$

Current passing

$V= IR$

Where

V = is the potential

I = is the current

R = is the resistance

$I = \frac{V}{R}$

$I =\frac {6V}{0.0425\Omega}= 14.11$ amp