Four factors that determine the resistance of a material
1. Type of Material -- copper less resistance than wood
2. Length The resistance of a material is directly proportional to its length. The longer the material is, the more resistance it has. This is because the electrons must flow through more material, and therefore meets more friction over the entire distance.
3. Cross Sectional Area
The resistance of a material is inversely proportional to the cross sectional area of the material. This means that the thicker the substance is across, the lower the resistance. This is because the larger the cross sectional area is, the less friction there is over a given length. (Picture in your mind, if you will, that a fire hose will pass more water than a garden hose, because the wider the pipe, the less resistance it has).
In various types of materials, resistance can vary inversely or directly with the temperature. This is because of the chemical properties of the material. In Carbon, for instance, the resistance decreases as the temperature rises. So we say it varies inversely. In copper, however, the opposite is true, with the rise in temperature, we have a rise in the resistance.