Question

State the law of length for an electric resistance.

Answer 1

The resistance of a conductor is directly proportional to its length, provided its material, area of cross-section and temperature remain the same. If R is the resistance and l is the length, then R ∝ l, i.e. R = constant × l.

For two conductors made of the same material, `R_1/R_2 = l_1/l_2`. So, if the length increases, the resistance increases; if the length decreases, the resistance decreases.