Besides temperature, experimental results shows that the resistance (R of a given conductor) also depends on the composition and size.

**Resistance**, R is found to be:

- directly proportional to its length, L
- inversely proportional to its cross-sectional area
- dependent on the type of material

From experimental results, we can show that:

$R = \rho \frac{L}{A} $

,where

R = resistance in ohm ($\Omega $)

A = cross-sectional area of conductor in metre^{2} (m^{2})

L = length of conductor in metre (m), and

$\rho $ = resistivity of material in ohm-metre ($\Omega m$)

**For the similar lengths and material,**

Thinner wires have higher resistance than thicker wires.

**For similar thickness and material,**

Longer wires have higher resistance than shorter wires.