PHYS-440 2024S
Measuring μ0 , the Magnetic Constant
brie
February 2, 2024
1 Abstract
. First consult the helpful document in the reading folder: /reading/how to write an abstract.pdf
.
. The above template is good, but a bit long. Somehow you need to condense your paper into a paragraph of approximately 100 words. This abstract is also very ‘fancy sounding’ . When you write you should always be writing for simplicity. This is why knowing the audience is critical. In the abstract above, a person without significant knowledge of that field (meaning me) would not be able to read it.
2 Introduction
. Start with an introduction and reminder of what μ0 is! Where is it relevant? What does it do? . Why do we care about it?
. Gently introduce the concept of the experiment. I can imagine some sentences like: “In this experiment we will balance the known force of gravity against the magnetic force between two current carrying wires. The strength of the magnetic force is contingent on the magnetic permeability of free space, which we aim to measure.”
. Nowhere should there be gross technical details. It’s unlikely amps, resistors, lasers, etc should appear anywhere in your introduction.
3 Background
1. Keep in mind your audience is 210 students. Remind them about the physics we discussed on the board the first day.
2. State up front what you are trying to communicate. It’s probably something like “what is the magnetic force between two currents?” .
3. A reasonable starting place is Maxwell’s Equations and the Lorentz force law.
4. You will almost certainly need a diagram. Figures are crucial to papers. Most professional scientists (me included) think about writing a paper first in terms of “what figures will I include in my paper?” and then work their writing around them.
5. Remember this is a narrative, not a mathematical proof (although there is no harm in being rigorous). You want to guide the reader gently through the diagram and the problem with nice prose. Always (at least 99% of the time) incorporate equations into your sentences.
6. Remember all figure captions should be detailed. Every figure should be referenced in the text.
4 Experimental set-up
1. Here you can get into the details of the technical setup.
2. Remember start simple/general/high-level and then go into details! Never the other way around.
3. You will almost certainly need another figure here. You could take it from the lab manual, but you must cite it. An actual picture of your setup could be nice too.
5 Results and Analysis
1. Time to present your data taking process clearly. Many students unceremoniously present the answer as
if the experiment, once built, whispered it to them sweetly. What was your data taking process?
2. Everything should have labels, units, etc.
3. I think a table of all variables, mean values, and errors would be nice.
6 Discussion
1. I write ‘discussion’ rather than ‘conclusion’ because often people interpret ‘conclusion’ to mean “let me summarize the paper, which essentially repeats the abstract”. This is not that.
2. Typically in a discussion, one would remark on the quality of their own experiment. Did your answer match accepted value? Was the error small? If the error was small, but your result was off the mark, why would that be?
3. Where did sources of error come from? Any student caught writing “human error” will be forced to listen to Rod Stewart on repeat.
4. How could the experiment be improved?
5. Be critical of your own experiment in a detailed way. But, it’s not all negative; if things worked out well, write how you ensured that!