Factors Affecting Resistance

Factors Affecting Resistance:

Material
Diameter
Temperature
Length

Four factors determine the resistance of a material to the flow of electricity. The first is the type
of material.

As you have already learned, conductors are made of materials, such as copper and aluminum,
that allow the flow of electricity because they do not have much resistance. Insulators, though,
are made of materials with a high level of resistance

The shape of the material is another factor that affects resistance.
The diameter of a wire, for example, helps determine the resistance of an object ‐ more material
for current to flow through means less resistance.


A wire that is very thin has more resistance than a similar wire that is much thicker.
Temperature is another factor that affects resistance.

A hot wire will often have a higher resistance to the flow of electricity than a similar wire that is
cold.

Length also affects the resistance of a wire.
A long wire will resist electricity more than a short wire if they are made from the same
material, are the same thickness, and are at the same temperature.
Determine whether the following wires will have more resistance or less resistance than a 1 foot
wire made of copper. The wire is 1/16th of an inch in diameter and is at room temperature.
more resistance

A wire 30 feet long having the diameter of a human hair
The original wire heated up in a furnace less resistance

A 1 inch wire with a diameter of 1/4th of an inch
The original wire cooled down in liquid nitrogen.