Investigating the Factors Which Have Impacts on the Resistance of a Wire

Investigating the Factors Which Have Impacts on the Resistance of a Wire

Introduction /Background information:

The electrical resistance of a circuit component or device is defined

as the ratio of the voltage (electric potential energy per unit

charge, measured in joules per coulomb = V) applied to the electric

current (the rate of charge flow past a given point in an electric

circuit, measured in coulombs/second or Amps = A) which flows through

it:

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Resistance = Voltage / Current

If the resistance is constant over a considerable range of voltage,

then Ohm's law which states that: The electric current which flows

through many conductors (devices designed to transmit electricity,

heat, etc.) of electricity is directly proportional to the voltage

applied to them; I = V/R, can be used to predict the behavior of the

material.

Whether or not a material obeys Ohm's law, its resistance can be

described in terms of its bulk resistivity (the electrical resistance

of a substance of a standard length and cross section). Thus the

resistance is temperature dependent. This temperature dependence can

be predicted from the fractional change of the resistance in Ohms.

Before starting my experiment I have decided to choose a factor that

will affect the resistance of a wire.

I shall do this by going through all of the factors that affect the

resistance of a wire and reasons why they affect the resistance of a

wire. From this list of factors I shall only pick one factor to

investigate and that will be the length of the copper wire.

Factors/Hypothesis

- The material of the wire. (What the wire is made out of):

The type of material will affect the amount of free electrons which

are able to flow through the wire. The number of electrons depends on

the amount of electrons in the outer energy shell of the atoms, so if

there are more or larger atoms then there must be more electrons

available. If the material has a high number of atoms there will be