In this case study, I will be investigating what affects resistance; I will be looking at the different aspects, and comparing them during the investigations, which will be taking place in class. I will be doing my investigations and experiments with my peer ‘Coelbie Powell’. Resistance is the ability for a component to prevent or resist the flow of an electrical current. This component would resist the electrical current due to the collision between the electrons and atoms, this then slows down and converts some of the energy, into heat energy.
“’n some cases, the energy is also converted into light’. Diagram Four Main things that I was able to change about the wire to change its resistance was: 1. Thickness – When using a thin wire, there is less room for the electrons to move, so the electrons are being prevented to flow. 2. Using a different material – Using a different material will determine the different atoms. Some atoms will charge better than others, therefore will be a better conductor. This means that there is less moving charges to carry the current.
Many other atoms will be willing to lose electrons on their outer shells. This is why the resistance of a wire depends on the configuration of the atoms that the material of the wire is made from. 3. Length – When increasing the length of the wire, it increases the length of the path that the moving charges have to pass, so the charges are likely to face collisions with other atoms that are not moving. 4. Temperature of the wire – Once increasing the temperature of the wire, it increases the resistance because the atoms of the wire gain more energy as it heats up.
When the atoms heat up, they vibrate faster, causing more collisions, which then increase the amount of resistance. Length gave the biggest variation in resistance and that thickness didn’t change the resistance much. Also that temperature was too difficult to control and measure. That’s why you decided to investigate length. In the investigation it was vital to keep all the factors the same because if I did not, then it would make the results inaccurate, and give me inaccurate conclusions.
When trying to keep the material of the wire the same, it should be quite simple because all that needs to be done is to be aware of the certain wires and what packages the wires are coming from, so that I do not get mixed up. Keeping the temperature the same will be quite hard, because controlling the temperature will be challenging. Keeping the factors the same: It is vital to keep all the factors the same because it will interfere with the results and I will fail to get to the true value, so the investigation will not be reliable. Preliminary Tests The material used was constantan.
Range Length – cm Voltage – V Current – A My longest will be 100cm, because 150cm was too long. The shortest length will be 10cm, because 5cm seemed to be too short, and while observing peers experiments, I saw 5cm wasn’t a good length due to lack of range. Thickness Voltage – V Current –A Thin 0. 7 0. 6 Thick I decided to choose the thick material because there is more room for the current to flow, and the material could become a health hazard if it was a shorter length. Power Pack Settings.
Current at longest length Current at shortest length I decided to choose 2V because it showed a good result and didn’t become too hot like 3V or absolute no change like 1V. The Interval? Change in length – cm Voltage change Current Change 20-30cm Practical set up: I decided to arrange the circuit having the volt meter vertical across from the power pack, while the ammeter is connected on the left hand side to the power pack and by using a ruler to keep the wire straight so it is more accurate.