# Pysics invstigation as to what factors afect resistance in a circuit.

Essay by mmanning July 2003

To investigate how the electrical resistance of a wire changes in relationship to its length.

Physics Investigation Of Resistance

Aim: to investigate how the electrical resistance of a wire changes in relationship to itÃÂ´s length.

Prediction: I think that as the length of the wire increases so to will the resistance of it. I also believe that the rate at which the resistance of the wire increases will be directly proportional to the length. The graph to show this should therefore look something like this:

Reason: with electricity, the property that transforms electrical energy into heat energy, in opposing electrical current, is resistance. A property of the atoms of all conductors is that they have free electrons in the outer shell of their structure. All metals are conductors and have an arrangement in similar form to this:

As a result of the structure of all conductive atoms, the outer electrons are able to move about freely even in a solid.

When there is a potential difference across a conductive material all of the free electrons arrange themselves in lines moving in the same direction. This forms an electrical current. Resistance is encountered when the charged particles that make up the current collide with other fixed particles in the material. As the resistance of a material increases so to must the force required to drive the same amount of current. In fact resistance, in ohms(R) is equal to the electromotive force or potential difference, in volts (V) divided by the current, in amperes (I) - OhmÃÂ´s law.

As the length of the wire is increased the number of collisions the current carrying charged particles make with fixed particles also increases and therefore the value for the resistance of the wire becomes higher. Resistance, in ohms (R) is also equal to the...