Question

If ρ is the specific resistance of a conductor of length ‘l’, area of cross-section ‘a’ and resistance ‘R’, what is the relationship between ρ, l, a and R?

Answer 1

The resistance of a conductor is directly proportional to its length and inversely proportional to its area of cross-section. Therefore,

\[R = \rho\frac{l}{a}\]

Equivalently, the specific resistance is

\[\rho = \frac{Ra}{l}\]

Thus, resistance equals specific resistance multiplied by the length of the conductor and divided by its area of cross-section.