Phys lab report

Lab Report Criteria 

 

Format

· Margins 

· “Moderate” 1 inch top and bottom, 0.75 inch left and right 

· Main title is 16 pt bold

· Section headlines are 14pt bold

· Subsections are 12pt italicized

· Font is 12 pt times new roman 

· Everything is justified block text 

· Abstract is with an additional 1 inch margin on left and right (1.75 inch total) 

· Cover page 

· Requires Name, Date, Class & Section information 

· Try to avoid pronouns (me, we, theirs, our, she, mine, my, etc.)

· Avoid contractions, write do not instead of don’t and cannot instead of can’t, etc.

· Equations must be entered in equation editor and numbered

· All images, tables, charts, and graphs need to be labeled directly below them. 

· In size 10pt font with the object and number in bold and the description regular  

Figure 1: These words describe the picture. 

Figure 2: These words describe the picture. 

Image 2: words describing image. URL-Of-Image-Main-Page 

Graph 1: These words describe the graph. 

Table #: The above displays blah blah blah. 

Tips & Tricks for Writing Your Report

· Putting equation numbers is hard in word, I use a 3 row one column table and put the equation in the middle column and the number in the left. I then remove all the borders.

· The equations can be boring to type over and over… copy and paste works!

· For references just type the number than hold shift back arrow, then ctrl+2. It will make it superscript instantly.

· I would do the abstract last it’s the most difficult part. (personal opinion)

· Procedure and apparatus are the easiest! (personal opinion)

· Calculations is worth a lot and isn’t too difficult either!

· Make sure Word is displaying the ruler. You can easily squeeze text under an image/graph by highlighting it and then dragging the arrows on the ruler where u want that text to go.

· Google is your best friend for Word and Excel questions

Magnetic Field in a Current Carrying Coil

Student Name*

*Electricity & Magnetism Laboratory, Department of Physics, University of North Texas, 1155 Union Circle, #311427, Denton, Texas 76203

21 July, 2020

Abstract: The abstract is typically 10 to 15 sentences and requires five main components. Each component is usually around two to three sentences long. First, what is the experimental objective? This will not be something one is trying to learn, rather it will be the verification of something such as a derived equation. Second, how will it be tested? What kind of apparatus are you using and how will it verify this. Third, what are the error percentages and are they high or low. You must include the numerical error values here. Fourth, why is this lab important? Or explicitly, why is it important to verify this objective. Fifth, how does the apply to the real world. Components four and five may sometimes be combined into one statement.

Introduction

This is where you explain you understand the underlying concepts that are being verified/tested. For lab 8 you will basically be outlining important and relevant information from chapters 21 and 22 of “Cutnell and Johnson physics 10th edition” and/or your lab manual. It is up to you to verify what is important and relevant in the text. You may even find other information from other chapters important. As an example: Newton’s Second Law1, given mathematically as:

(1)

Where is a vector known as the force on an object and is measured in Newtons, m is the object’s scalar mass measured in kilograms, and is a vector known as the object’s acceleration measured in or meters per seconds-squared, is very important. However, this equation is not relevant to this experiment and probably doesn’t need to be included in the introduction. Meanwhile, the equation for resistivity2 given as:

(2)

Where is the resistivity of a material in or Ohm-meters, E is the magnitude of the electric field in said material measured in Newtons per Coulomb, and J is the magnitude of the current density caused by the electric field measure in Coulomb-meters per second, is relevant. However, this is not important as errors for resistances in wires shouldn’t affect the experimental results too much.

When writing the introduction section, one should start from the “bare bones.” There are electrons which under a potential different in a wire cause current flow. Current flow is associated with moving charges which in turn creates a magnetic field. This is important because it explains where the scientific process began (in this case examining electrons), what changes it went through (potential difference across a wire to make electrons move), and where we are now (examining how this causes an electric field.)

Of course, to get to the bare bones, there is also some history involved! A sentence or two about magnetic phenomenon to set the stage for the introduction is permeant. This lets us start with also a basic human observation and leads us into the realm of science to analyze it. In this case a sentence or two about the ancient city of Magnesia being the first observational point of magnetized iron ore would do the trick.

One of the core pieces of a physics lab report’s introduction section is the derivation of the equation under investigation from what are considered fundamental principles. Also, it is important to state what kind of quantity every variable is (vector, scalar, etc.), what physical quantity the variables represent (magnetic field, number of loops, etc.), and what the units of each variable are. See the above examples of Newton’s Second Law1 and the Resistivity2 Equation (Note, your derivations will be a couple of lines, however only the final result, the one used in calculations, is numbered).

Typically, a derivation has a particular configuration in mind. It is usually hard to mentally visualize these so images/figures are used. These can be included as follows:

Figure 1: The above image depicts young Richard Feynman in front of a blackboard. https://www.britannica.com/biography/Richard-Feynman

The above image displays young Richard Feynman in front a black board which includes multiple equations from his famous quantum field theory. Notice how there is a short description of the image directly under it followed by my details in the text. In the case of the report the figure will probably be a loop or solenoid and you will state what it is under the image while in the text you explain the variables drawn on said image. If the image/figure is taken from the internet the main web address should be included under the image in the description (not the image URL location).

As a final note, consider this portion of the lab report as prime study time. You get out what you put in. The more details you cover and outline here, the better you will grasp the concepts/information which will directly cross over into your lecture’s homework and exams.

Apparatus

The next section of the lab report is the apparatus section. This is NOT a bullet point or numbered list. This section must be completed in complete sentences. A way to complete this is to use a colon followed by lots of commas! As an example: “The follow experiment requires the following: item 1, item 2, item 3, item…” When listing the items, you should include as much information about the item you can. This includes name, brand, serial numbers, etc. This makes it easier for future experimenters to verify your results through exact repetition. It is then necessary to explain how the equipment is connected. What is connected to what and how. “Item 1 is connected to Item 2 via USB 2.0 to USB mini cord. Item 2 is in turn connected to …” Next one must trace the signal path. In our case the signal will start as a current, which will turn into a magnetic field, and then measured by a magnetic field sensor to be converted to… until you reach readout. This may seem overkill, however the signal path is not necessarily the same as how things are connected and it is important to see these differences. Should there be an error in the data the first thing you would need to check would be your apparatus, however you cannot fix it if you do not understand how its connected/working in the first place! An image of the apparatus must be included.

Procedure

There are two subsections for the main procedure section. Both sections are in complete sentences, not bullet points or numbered lists. (Use words like First, Next, Then, Followed by, etc.)

Setup Procedure

There is where one explains how the apparatus was connected in practice. This may seem similar to what was done in the apparatus section, however it is slightly different. The apparatus says what is connected to what, not how and in what order it was connected. For more sophisticated apparatus it may be necessary to connect several pieces of together before putting them all somewhere else in the apparatus. This is where you would explain such things. For this lab however, this section may be near identical to the apparatus sections description.

Experimental Procedure

This is where it is explained what was done to obtain the data from the experiment. It includes everything, including what buttons where pushed and menus opened on a computer!

Data

This is where the data you obtained in the experiment is displayed in your report. This data should be put into tables as shown:

This (Units)	Is (Units)	How (Units)
A	Table	Is
Formatted	For	Lab Reports

Table 1: The above table demonstrates how tables are properly formatted for lab reports.

The title of the column is put in the top cell with units. The units are only placed in the title cell of a column, not on each entry (saves on ink/paper space if many copies are needed for something.) It is important to make your tables look professional. Part of this laboratory is to learn how to use a word processing software to achieve this. The table should be centered on the page with respect to the left and right margins. Text/data within the table should be centered justified (left/right and top/bottom.)

Calculations & Graphs

This is the section where all calculations are done. When doing calculations there is a format to be followed as displayed:

This is how each calculation should be done, and it should be done for EVERY calculated value (including percent errors, percent differences, and total expected errors). This may seem overkill however, this gives transparency. Should one say here is an example calculation the rest follow, the experimenter could have chosen their best data point and fudged the rest. This gives false results and is not scientific. From this laboratory standpoint, it also allows the grader to verify your every move to make sure you grasp the concepts. It also forces you to write the equation several times to engrave it into your memory and allows you more practice with the equation editor tool. Before however calculating one must reference the equation from the introduction. This allows for the reader to go to get any necessary background information of an equation later one. This may look as follows: From equation one and the data supplied in table one we calculate the force on the particle as

(1)

Notice how I referenced equation one in the actual calculation area as well. This would then be repeated for each data point, percent error, total expected error, etc. Note that even in this section a sentence or two was given to explain what calculations were being done and where the data/equation is coming from. It is not just “BAM MATH!”

The next thing included in this section are the graphs (Personal preference allows graphs to go in any of Data, Calculations, or Discussion that would flow more naturally to/for the writer/reader. Since the syllabus has this section titled calculations and graphs, graphs will be discussed here. Verify with your grader before moving graphs to a different section that it is acceptable.) Graphs require there to be: a title, labeled x & y axes with units, data points, a line of best fit, the equations of the line of best fit, the r and/or r2 values, and possibly a legend if there are multiple trend lines. Graphs are always titled y vs. x. An example is shown below using a position vs. time graph. Graphs should be fairly large so they are easy to read. Instead of making it smaller has been put on a new page. This graph was created via Microsoft Excel. One of the other major objectives of the lab report is also to become familiar with a data processing software such as Excel.

Graph 1: The above graph shows the position data versus the time data collected in the experiment during trial one.

Graph one above shows the position versus time data collected during trial one of the experiment.

Graph 2: The above graph shows the position data versus the time data collected in the experiment during trial two.

Graphs two above shows the position versus time data collected during trial two of the experiment. Notice again how you should repeat what the caption says, typically in more detail. However, in this case I have no extra details to provide. Full analysis of this graph will be done in the discussion portion of the lab report.

Discussion

This is the portion of the lab report where one goes into any problems with the lab, analyzes all the data, and talks about errors. As far as problems go one may talk about if something was connected wrong or if a resistor was burnt out, etc. One should also explain how the problem was resolved. This could be as simple as turning on a piece of the equipment or more complicated such as a faulty oscilloscope (which you wouldn’t know if you didn’t know the signal path to check!) This is also a good place to naturally start answering some of the questions in the lab manual. DO NOT just write the questions from the manual and their answers. These questions should arise naturally to which can be answered naturally. Think of the post-lab questions as a sort of guide in helping you navigate the discussion section.

You will also discuss the data in tables an analyze the graphs in this section. For each table you should have maybe a sentence or two (if any.) This is typically to state you notice the data is related in such fashions as linear, quadratic, exponential, etc. For each graph you should have typically a paragraph of analysis. This includes the trend you see between the plotted quantities (linear, inverse, logarithmic, etc.), what the line of best fit represents, what the x and y intercepts represent, what any slopes represents along with corresponding physical units (meters, amperes, ohms, etc.) of these items. There may even be times you see no correlation at all! In this case there is still plenty to talk about!

Next and possibly the most important portion of this section is the discussion of error. First and foremost: DO NOT SAY HUMAN ERROR ! When discussing errors in this lab we talk about random and systematic errors and compare them with percent errors, percent differences, total expected error, standard deviation, and qualitative amount of systematic error (Standard deviation divided by Total Expected Error). Standard deviation and qualitative amount of systematic error are above this course and require multiple trials (typically around 30 or more.) The first error, random error is always present. In any lab where the signal is an electrical signal, typical random errors are electrical noise and signal broadening. Random error can be seen in data by how much the data points spread around a trend line. In graph one, most of the points are on the line so there is little random error. However, in graph two, the data points are much further from the trend line and thus there is much more random error. The r values also correspond directly to a measurement of random error. The closer the r value is to one, the less random error there is. The closer it is to zero the more random error there is (a fine point is that the r value actually tells how close the data is to the type of fit chosen albeit linear, quadratic, whatever. However, in physics we typically know the type of fit required from the data plots and derived equations. Thus, we get to enjoy treating r as a measure of random error.) As for the typical mechanisms of random error, electrical noise is caused by capacitive coupling and inductive coupling which cause electrical signals to become coupled. This can be reduced by calibrating the apparatus (run the experiment without something causing a signal and set it to zero! Much like when you tare an electronic balance.) Signal broadening occurs due to the random motion of electrons in wires. If all the electrons of a signal start off together, they will not end together because each electron takes a different path. This means some of the signal gets to the detector before the rest of it.

The next error, systematic error, causes a shift in the intercepts of the data. Typically (but not always!) we want our data to pass through the origin. However, sometimes it does not. This could be caused by a systematic error. Systematic errors occur when a measurement adds the same offset to a given value. Let us say one wanted to measure the distance of a particle from a point. The particles distance is 1m, then 2m, then 3m. When measuring however you record 2m, 3m, 4m. Every point was offset by 1m. This is a systematic error. There was an error in the system/apparatus taking the data. Typically systematic errors are more difficult to find than random errors.

When discussing errors, it is also important to include the numerical values of percent errors, etc. and analyze them with regards to random and systematic errors.

Conclusion

The conclusion section contains two key parts. Did you verify your objective? How do you know? Elaborate how you know in terms of precision/accuracy. You will need to restate your numerical error values here to back up your claim. And how can you reduce errors in future runs of this experiment?

References

1. “Newton's Laws of Motion.” Sears & Zemansky's University Physics, 15th ed., Pearson, pp. 100–129.

2. “Current, Resistance, and Electromotive Force.” Sears & Zemansky's University Physics, 15th ed., Pearson, pp. 812–844.

It’s time to give credit where credit is due! All information should be referenced. If you noticed in the introduction when Newton’s Second Law and Resistivity were discussed, there was a superscript 1 and superscript 2. Those correspond to the numbers in the references section. If superscripts[1] are unavailable one can[2] also use the refences number in square[3] brackets like shown. References should be in numerical order. DO NOT3 DO SOMETHING1 LIKE THIS2. The exception1 is if you used something2 in the beginning3 and need to use2 it again at a later4 location in the paper such as this. Easybib.com is a great place to make reference lists fast! You should make a new reference number any time you change chapters/sections of a source. This just makes it easier to go back and find the information if you do not understand what you wrote in the first place. A typical chapter could be 100 pages but a section is usually much shorter and easier to skim through for what you are looking for. This is the only part of the lab report that may be in list format. You can also use internet sources! Just make sure to reference them! Note that copied images need the url under them in the description tag.

Position vs. Time

time

0 1.1000000000000001 1.9 3.3 4.2 4.8 6 6.9 8.1999999999999993 9.1 9.9 0 1 2 3 4 5 6 7 8 9 10

Time (s)

Position (m)

Position vs. Time

TIME

0.3 1.1000000000000001 1.5 3.6 7 5.8 2 7.3 7.5 11 10.8 0 1 2 3 4 5 6 7 8 9 10

Time (s)

Position (m)