Investigating how the Resistance of a Constantan Wire is Affected by Its Length

Investigating how the Resistance of a Constantan Wire is Affected by Its Length

Introduction: In this experiment we will be investigating how changing

the

length of a piece of Constantan wire will affect the resistance.

Therefore the length will be an independent variable and all of

the other variables we will try to keep the same. The other

variables included in this experiment are temperature, thickness

of wire and density of wire. Resistance is a force, which

opposes the flow of an electric current around a circuit so that

energy is required to push the charged particles around the

circuit

Key factors:

- Thickness of the wire: if the wire is thin, the electrons are forced

to travel through a smaller area, therefore colliding more frequently,

resulting in them giving up more of their energy to surrounding

particles.

- Temperature: resistance of the wire increases as the

temperature

increases, as the atoms are oscillating faster. When an electro

collides with an atom, it loses its energy. If the wire cools, the

resistance will decrease.

- Length of Wire: the longer the wire the larger the resistance, due

to the fact the electrons have a further distance to travel,

increasing the possibility of any potential collisions.

- Wire density: If the wire has a high density, the resistance will

be

Higher, as there are more atoms found in a smaller space. This leaves

less, and smaller, gaps for the electrons to flow through. Because of

the lack of space, we would expect there to be more collisions between

the atoms and electrons.

Preliminary results:

- The reason for doing preliminary research was to get an indication

of the patterns I could expect in my results. Also, it was considered

a practice, so if any errors were made in the first attempt, then they

could be eradicated in my real experiment.