Question

write and derive the relationship bewteen electrical resistivity of resistor of length L and are of cress section A. define the term resistor of a material and also derive its SI unit.

Answer 1

let’s assume we have a piece of wire (a conductor) that has a length L, a cross-sectional area A and a resistance R as shown.

The electrical resistance, R of this simple conductor is a function of its length, L and the conductors area, A. Ohms law tells us that for a given resistance R, the current flowing through the conductor is proportional to the applied voltage as I = V/R.