Explore how the resistance of a wire changes when we alter values affecting the resistance.

Authors Avatar

Resistance Wire Investigation

Planning

In this investigation, I plan to explore how the resistance of a wire changes when we alter values affecting the resistance. These values can be one of the following:

  • Power – I am to use the same current and voltage across the battery all the time – 3V
  • Cross-sectional area (thickness) – This will be kept constant, as a change causes a big change in resistivity. I will use a micrometer screw gauge at certain intervals along the wire. The wire size is 30swg
  • Heat – Again, this affects resistance, so I will try to keep heat constant
  • Density / Wire type – I will use constantan wire. I am not going to change either of these variables, as I do not have the resources available to me.

I am to carry out the investigation considering the length of the resistance wire. This wire will be made out of constantan allow. From a preliminary test, I have decided that it would be practical to take readings every 10cm. This is because it would take too long if any more results were found, and the collaborate data would be less accurate if less readings were taken.

As another accuracy control point, I have decided to take 3 readings every 10cm before taking an average. This will reduce the effect of anomalies if they do occur. Finally, the electrical wires connecting up the circuit also have an effect on the length of each interval. To reduce this effect, I decided it appropriate to take the reading from the furthest point on the ‘crocodile clip’ from the other end.

Join now!

In order to carry out the experiment, the following equipment will be used:

  • Resistance wire board (specifically the wire of 30swg)
  • Power supply
  • Voltmeter
  • Ammeter
  • Electrical leads
  • Micrometer screw gauge

Resistance is the property of any object (this case a metal) of resisting the flow of an electrical current. The quantity of resistance in an electric circuit determines the amount of current flowing in the circuit for any given voltage applied. The unit of resistance is ohms / Ω. The standard abbreviation for electric resistance is R.

The resistance of an object is determined by a ...

This is a preview of the whole essay