Question

The resistance of a conductor of length x is r. If its area of cross-section is a, what is its resistivity? What is its unit?

Answer 1

Resistivity of a conductor, $\rho =R\frac{A}{L}$
Here, L = x, R = r and A = a
Therefore, $\rho =r\frac{a}{x}$
The unit of resistivity is ohm-metre ($\mathrm{\Omega }\mathrm{m}$).