Term papers writing service


What is the resistance in a wire essay

The Resistance of a Wire Essay

Hire Writer I believe this as whilst investigating my preliminary experiment, the wire burnt quickly on a voltage of 8V or thereabouts. I predict that the shorter the wire becomes, the higher the voltage and current of that wire, I believe this because the shorter the wire becomes, the lower the resistance becomes as the free electrons in the circuit would have far less atoms in the Constantan wire to impact against subsequently lowering the resistance.

  • I would strive to collect resistance readings that were the same throughout the experiment as mine varied slightly;
  • Therefore it is important to keep the material the same throughout the experiment unless a different material is used to check if the conclusion or theory works for all materials;
  • Thickness — thin wires have more resistance than thicker wires, because there is not as much space inside the wire, which means the electrons have a lot more resistance inside the thinner wire than the thicker wire;
  • Cross sectional area Voltage is the measurement of the energy of each charge;
  • Analogue Ammeter and a 0-5 Amp d;
  • Hire Writer I believe this as whilst investigating my preliminary experiment, the wire burnt quickly on a voltage of 8V or thereabouts.

Also I predict that the higher the voltage and current on a short length of wire, the higher the possibility of mass temperature rise and therefore open flame. This would ruin the experiment so as I have said before I shall only be using voltages less than and including 6v. Final experiment During this section of the investigation, using newly discovered knowledge from my preliminary experiment I shall aim to collect a set of accurate results to match my hypothesis.

Apparatus During this experiment I shall need: A digital ammeter A digital voltmeter A Constantan wire A power pack Sets of power leads 100cm ruler Crocodile clips Diagram Method The apparatus was set up as shown in the diagram. The Constantan wire was mounted onto the ruler, and attached by both selotape and crocodile clips one at 0 on the ruler, the other one was moved up and down the scale in order to change the overall length of wire included in the circuit The readings were taken from both the ammeter and the voltmeter in two sets for each voltage.

As the voltage and current have increased the resistance has increased, as I have previously stated in my prediction, therefore Constantan wire obeys ohms law of resistance.

Resistance of a Wire

The increase in resistance is due to more and more energy being put into the wire. That is to say as the voltage or the driving factor behind the free electrons flowing around the circuit increases, this increase in resistance is caused by the free electrons being passed around the circuit at much higher speeds and therefore deflecting off of more atoms that have more heat energy than those in shorter lengths of constantan wire.

  1. The resistance of a metal wire increases as the temperature goes up.
  2. The experiment was completed with so many problems. They are attracted to the positive terminal and repelled from the negative terminal.
  3. Temperature The resistance of a metal wire does change with temperature and despite keeping the voltage low, the temperature of the wire will have changed during the investigation.

These atoms are hotter because more free electrons are passing through these lengths of wire, and deflecting off of more atoms, passing their kinetic energy to these atoms as heat energy.

This is what causes the wire to heat up, and sometimes melt. During taking these results I have noticed that there are several linking factors. These are mainly current and voltage, as stated in ohms law. Evaluation I believe that my experiment in all is accurate for a GCSE standard coursework piece, although in research physics I believe that this experiment would be highly inaccurate. I do not believe that any of my readings are abnormal.

From my work — mostly from the average set of results taken from all 6 sets, I can conclude that: If I had the power pack on for too long a period of time, the readings on both ammeter and voltmeter began to become more and more erratic.

  1. They are attracted to the positive terminal and repelled from the negative terminal. To make the experiment reliable, all apparatus must be checked to see if it is functioning properly and is giving a true reading.
  2. The smallest scale division on the 0-1A scale was 0. How to cite this page Choose cite format.
  3. I predict that the shorter the wire becomes, the higher the voltage and current of that wire, I believe this because the shorter the wire becomes, the lower the resistance becomes as the free electrons in the circuit would have far less atoms in the Constantan wire to impact against subsequently lowering the resistance.

I believe this to be because the apparatus was not turned off, heat would have been building up in the Constantan wire so during the experiment I turned off the apparatus between readings. After I did this I noticed that this strange behaviour had stopped. I also realised that using a rule and crocodile clips was clearly not the greatest means of measuring the length of wire as the lengths would clearly have not been at all accurate, and that the likelihood of using the exact amount of wire in the circuit was far outweighed by that of not doing so.

In the graph which I associated length of wire with resistance, it clearly showed a straight line through the origin 0,0. Improvements My work in this final experiment is far improved from that of my preliminary although it could easily still be improved further. I would improve it further by using more accurate means of measuring the voltage and current of the circuit, I would use various types of wire, I would vary the temperature of the wire and I would vary the cross sectional area of the wire.

In this experiment, although I only varied the length of the wire, unwittingly I also have changed the temperature of the wire, as it increases as any current is passed through it, and as the shorter the subject wire becomes the hotter it also what is the resistance in a wire essay. I would strive to collect resistance readings that were the same throughout the experiment as mine varied slightly. Reliability I believe that my results are viable for a GCSE standard piece of coursework although a research physician would discard them.

Constant factors In this investigation I have strived to make sure that the following factors remained constant: This reason also dictates that the type of wire is also a factor that was kept constant. As I have mentioned before the temperature of the wire would have varied throughout the experiment, and as I have mentioned in the preliminary section of this investigation that with voltages higher than 8v the wire began to burn.

This deviation in the temperature may have been the deciding factor as to why my readings for resistance were only slightly different.

  • This could have been achieved by placing a large value resistor in series with the wire — say 0-5000 Ohms;
  • This increases the amount of collisions therefore there is more resistance;
  • A large amount of heat energy is needed to change the temperature of the water bath because of the high value for the Specific Heat Capacity of water.

Show preview only The above preview is unformatted text This student written piece of work is one of many that can be found in our GCSE Electricity and Magnetism section. Download this essay Print Save Not the one? Search for How to cite this page Choose cite format:

Resistance in a wire