Conclusion and Evaluation

□ You state a conclusion based on a logical interpretation of your data

□ If you made a hypothesis you evaluate the truth of the hypothesis.

□ If you are measuring a well known quantity, (like absolute zero) state its value and give it a bibliography reference.

□ You discuss the limitations of your research (sources of error)

□ You suggest improvements that could be made to minimize your cited sources of error – or other things about your work that could be improved.

□ You suggest work for further research (thereby reflecting your personal curiosity for the subject)

□ You include a bibliography for any sources cited

Here is a great example of a conclusion - Paige Lawton, 2022

Conclusion:

The purpose of this experiment was to determine the relationship, if any, between the current flowing through an electromagnet and its force of repulsion. The data gathered clearly supports my hypothesis, increasing the current in the solenoid resulted in an increase in force. This repulsion is due to the gradient in the magnetic field:

In the diagram above, the blue curve represents the magnetic field due to the coil, pictured on the left. On the right is the permanent magnet I used to generate a repulsive force. The magnetic field is stronger closer to the coil and weaker further away.

The north side of the permanent magnet is closer to the coil and so it is being repelled quite strongly. Whereas, the south pole being farther away is in a weaker magnetic field and is therefore being attracted with less force. So the net overall force is that of repulsion. This force of repulsion was my dependent variable.

The force of repulsion is increasing with more current(A) because the gradient in the magnetic field is also increasing:

The graph on the left represents less current and the graph on the right represents more.

With less current there is less of a field difference from one end of the magnet to the other, so therefore less repulsive force. When the current is more, the gradient increases also widening the disparity between repulsive and attractive forces resulting in a greater force of repulsion. Since the gradient of this field increases in proportion to the overall magnitude I would expect it to be a linear relationship.

Evaluation:

The use of a triple beam balance to measure the masses provided some level of error in the results. Manually moving the sliding weights provided a level of inaccuracy to the dependent variable data that was gathered. Since the current(A) was increased by only 0.250A each variation, the data points had very small differences. The distance to move the sliding weights was very small each time and quite hard to execute without flaw. In order to counteract this, doing more trials would be able to help eliminate this source of error. In addition to more trials, a digital scale would be a very precise option. If the distance could remain constant, a digital scale would eliminate the possible human error that comes with moving the sliding weights. The small increase in current(A) would not be an issue for the digital scale as it would have no issue with changing the reading by a small amount.

Another flaw in the method of this experiment was the inconsistency of the ammeter’s readings. Once the current(A) was set for one variation, the reading would fluctuate around the set current(A). This inconsistency in current(A), while minimal, can definitely affect the accuracy of the data gathered. Since a triple beam balance was used, the mass was not immediately found. The sliding weights needed to be adjusted to the new current(A) and this can take up to a minute with the fluctuating current(A) and tediousness of the minimal increase in mass. During this time, the current(A) would deviate from the intended current by as much as +/-0.100(A). This value is almost half of 0.250A, the difference between each variation, which poses a significant source of error in the data. To counteract this fluctuation, more trials would need to be done. With more trials the impact of errors is minimized because the more times you collect data, the closer the average is to the true value. More trials allow more confidence in the results of the data when supporting or not supporting a hypothesis.

The temperature of the solenoid also played a role in the accuracy of the results. As the current(A) flowing through the solenoid reached around 4.00A, the temperature of the solenoid began to increase rather quickly. The solenoid reached high enough temperatures to produce a burning aroma in the area where the experiment was conducted. To create a safer environment while gathering data of higher currents(A), the flow of the current was stopped in between the variations 4.00A and 5.00A for 1-5 minutes to allow the solenoid to cool down to a reasonable temperature. This definitely could have caused discrepancies in the data as the current flowing was not a constant current throughout the entire experiment. To counteract this error, using a solenoid with more windings of coil would allow more current(A) to flow through the coil without the temperature getting too high. With more windings, there is more wire for the current(A) to flow through allowing the solenoid to stay cooler longer. However, even when using a solenoid that could withstand more current, allowing the solenoid to cool down between each trial would be a great preventative measure to ensure that it does not overheat.

Further Research Suggestion:

If I were to perform this experiment again, it would be interesting to see how different the results would be with more precise instruments and minimizing the sources of error. In addition to doing the same experiment again, having different distances between the solenoid and the permanent magnets and analyzing the effect of distance on the force would be a fun twist on the experiment. With my extended knowledge of the results of this experiment, being able to see the effect that distance has on the force of repulsion would be fascinating and give me more insight into magnetic fields on a greater scale. While I’m not quite sure how I could conduct an experiment involving electromagnets and computers, that would be a very fun experiment to conduct. Combining my love for physics and computers would be the best of both worlds.