Question

While finding the resistivity of a wire, what is the unit for the cross-sectional area of the wire?? Given that the formula is:

Resistivity = (resistance / length) * cross-sectional area ?

Answer 1

the unit is that of area. If you are using SI units (which you should be using), then it will be in square meters. The units for resistivity are Ohm-metres or \(\Omega m\). This can be shown by plugging the units into the equation \[\rho=\frac{\Omega}{m}m^2=\Omega m\]

Answer 2

As long as you have teh length of the wire and the area in teh same bas units (for example centimeters and square centimetres, you will be fine. In this case the units for resitivity will then be \(\Omega\rm{cm}\)