Plot a graph of results and draw a line of best fit. Below is a labelled diagram of the experiment: Variable Battery Resistor Switch Voltmeter Ammeter Wire Boiling Tube Constantia Wire Ice Prediction Using my scientific knowledge on resistance I can make a prediction.
I predict that the wires which measure 40cm and 50cm will have a low resistance respectively, because there is a shorter length for the current to travel. Meaning less collisions between the atoms of the wire and the electrons of the current. Also the electrons do not have to squeeze together for a long amount of time, because these lengths of wire are only short. Also as the lengths of these wires are only short, as the electrons squeeze together to be able to pass through the wire, there will be less collisions between electrons and other electrons, because there is only a short distance for the electrons to travel.
Using my scientific knowledge I predict that the wires which measure 80cm and 100cm will have the highest resistance respectively because there is a long length which the current has to flow along. As a result there will be a large number of collisions occurring between the atoms of the wire and the electrons in the current. Adding to this the electrons have to squeeze together for longer than they do in a short wire to be able to pass along the wire, resulting in more collision between electrons and other electrons because there is a long distance for the electrons to travel.
Finally I predict that the 60cm wire will have a resistance that is greater than that of the 40cm of 50cm wire, yet will have a smaller resistance than the 80cm or the 100cm wire. I predict this because 60cm lies between the long wires and the short wire. This means that the resistance of the 6ocm wire will not be high however it will not be low. I predict that the graph will show a strong positive correlation. I predict this because as the voltage increases the current also increases. This is how I think the graph will look: Analysis.
After completing the experiment I have discovered that my prediction that the 40cm wire would have the lowest resistance and followed by the 50cm wire was correct. These two lengths of wire had the lowest resistance because there was a shorter length for the electrons in the current to travel. Therefore there would be fewer collisions occurring between the positive atoms of the wire and the negative electrons of the current. Also the electrons don’t have to squeeze together for a long time, because compared to the other wires which are a lot longer in length, there is only a short distance to travel.
The graph displays that the 40cm and 50cm wire had the smallest resistance respectively, because the lines which represent these two lengths have the least steep gradient. These results show that my planning worked . The results illustrate that placing the ice in the boiling tube, and then wrapping the wire around the boiling tube worked in stopping the temperature rising. The graph also supports this because the gradient of these two lines which represent these two lengths was not at all steep. On the other hand my prediction that the lengths of wire measuring 100cm and 80cm would have the greatest resistance respectively, was incorrect.
I predicted that these two lengths would have the highest resistance because there is a longer length for the current to travel along. This would result in the current carrying the electrons taking longer to travel along the wire. Also the collisions between the atoms and the electrons would occur more frequently because there would be more atoms in the wire, because the lengths of these two wires were longer than the other lengths used. As these lengths are very long the electrons would have to squeeze together for a long time to be able to pass through the wire.
I predicted that there would be more collision between electrons and other electrons, because the electrons have to squeeze together for a long time. Despite all of this evidence the 60cm wire had the greatest resistance. The graph illustrates this because the gradient for the 60cm line is the steepest out of all of the results. This was an unexpected result. I didn’t expect the 60cm wire to have the most resistance because the 100cm wire is 40cm longer and the 80cm wire is 20cm longer. The 100cm wire and the 80cm wire are a lot longer than the 60cm wire therefore the two lengths should have had a higher resistance.
This result suggests that the theory that placing the ice inside the boiling tube and then wrapping the wire around the test tube to stop the temperature from rising doesn’t work. However if this is true why didn’t the 4ocm wire and the 50cm wires have a higher resistance. I think that placing the ice inside the boiling tube did stop the temperature rising therefore stopping the resistance from rising. Another reason why the 60cm wire was an anomalous result is that this wire could have already been used. If this is true the wire might have still held an electrical charge.