Already by looking at Data Table 1 and 2 a clear pattern can be seen, that when the current IS increases, so does the force. Graphs of F versus IS can be found on the following page. Thereafter is a graph showing the relationship between F and IB. The graphs very nearly do go through the origin. Therefore to calculate the slope we need to find F over IS. The slope for when IB = 4A is 4.55 10-4. The slope for when IB = 2A is 2.33 10-4. What this shows is a clear positive relationship between the force and the current running through the wire. In other words, the more current, the greater the force will be. To calculate the magnetic field strength, B, inside the solenoid: Using 4.55 10-4 as the slope and 0.029 as the length of the solenoid, our answer for the strength of the magnetic field is 0.016
Furthermore, the relationship between the force and the current through the solenoid (IB) is also a positive relationship. In other words as the current in the solenoid increases, the force does so too. To find the magnetic field strength B inside the solenoid per ampere of current IB through the solenoid: Using 3.2 10-4 as our slope, 3A as our current IS, and 0.029m as our L, we get the following k value, 0.0037. This is the magnetic field per ampere in our solenoid.
Conclusion: By observing my graphs I can see that I was correct in my hypothesis to predict that the current going through the solenoid and the force exerted are proportionally related. Our graphs show near-linear positive relationships that nearly go through the origin (like I predicted in the hypothesis). When we graphed F versus IS there was a clear positive relationships between the two, in other words as Is was increased, F proportionally increased as well.
To answer the question of how does the field inside a solenoid vary with the current through the solenoid, the following can be concluded from our results: as the current through the solenoid varies (increases or decreases), the effect on the field inside the solenoid will be the identical variation (increase or decrease). In our graphs we used interpolation to see whether the graph would cross the origin (0,0) which should be the case. In all three graphs this was close but several factors could have led to differences between our experimental results and the predicted results (discussed in evaluation)
Evaluation: Although for the purposes of our experiment, the validity of our graphs is more than sufficient; there are still minor errors that could have altered the slightly off linear trend. Already from the start of the experiment it was difficult to classify exactly what it was to have the strip “balanced”. Balance was nearly impossible to quantify in our experiment and it was left largely debatable as to whether or not there was perfect balance. Moreover, since we dealt with such small numbers throughout the experiment it was often difficult to get either a smaller mass, or even a smaller amount of current.
Some additional activities that could be considered for the future would be to design an experiment to show that the field produced by a solenoid is uniform within the interior of the solenoid (because here we assumed this). Also we could investigate having the strip and the solenoid connected in series so that the same current runs through both and investigates the force versus the current relationship.