Physics 2 Lab
PHY 2231/2431
Section __4__
Lab Title:_Spectrum____
Instructor:__Farhad Ghoddoussi____
Name:__ Daniela Scagnetti __
Date:____10/12/2022________
Partners:___Alanna Makarchuk,
Maria Lomas, Nicole Balek
LTU Honor Code:
I have neither given nor received unauthorized aid in completing this work, nor have I
presented someone else’s work as my own.
Signature:________________________
Ohm’s Law – Data Analysis
Data Analysis
You studied Ohm’s Law and applied linear data fit technique in this experiment. A similar
experiment was conducted for an unknow resistor. The following data was obtained. Please process
the data to determine the unknown resistor.
Data Run
1
2
3
4
5
6
7
8
9
10
Voltage (V)
1.414
1.872
2.453
3.681
4.485
5.304
6.214
6.88
7.49
8.15
Current (A)
0.036
0.048
0.063
0.094
0.115
0.136
0.159
0.176
0.192
0.209
Data Run
11
12
13
14
15
16
17
18
19
20
Voltage (V)
8.83
9.44
10.21
11.15
11.84
12.54
13.31
13.97
14.58
15.57
Current (A)
0.226
0.242
0.262
0.286
0.303
0.321
0.341
0.358
0.374
0.399
Question 1: (4 points)
With the data points, please make a I - V plot using Microsoft Excel; include a linear fit to the
data points, and show the linear fit function with the plot. Attach the plot below. (Refer to the
example in the lab manual.)
Question 2: (4 points)
Please calculate the unknown resistor using Ohm’s Law, and report your results based on the unit
given in the header.
Data Run
1
2
3
4
5
6
7
8
9
10
R (Ω)
39.28
39.00
38.94
39.16
39.00
39.00
39.08
39.09
39.01
39.00
Data Run
11
12
13
14
15
16
17
18
19
20
R (Ω)
39.07
39.01
38.97
38.99
39.08
39.07
39.03
39.02
38.98
39.02
Question 3: (4 points)
Please determine the statics of the unknown resistor, and report your answer below. Your answers
must be truncated to the correct number of significant digits, and be reported in scientific notation.
(Please refer to the Uncertainty.pdf file for how many digits to keep; points will be deducted for wrong
format.)
R (Ω)
Mean
Standard
Deviation
Standard
Error
95%
confidence
range
Minimum
Maximum
39.04
0.08
0.02
Mean +/- 0.03
38.94
39.28
Question 4: (4 points)
What is the resistance value determined from the linear data fit technique? Does it match the
resistance value determined from the statistics within its 95% confidence range?
From the graph, the resistance value is the reciprocal of the slope, which came out to be 39.06 for this
data. The average resistance was 39.04, and the 95% confidence interval for this average was
between 39.07 and 39.01. This means that the graph’s resistance value falls within the 95%
confidence range for the data points.
Question 5: (4 points)
Is the minimum resistor value, or the maximum value, an outlier? Please refer to the Chauvenet’s
Criterion in the Uncertainty.pdf.
The minimum value of the data set is 38.94 Ohms, which was not an outlier in this data according to
Chauvenet’s Criterion. Chauvenet’s Criterion finds an allowable percentage of data occurrences as
determined by the ratio difference from the mean and the standard deviation of a set of data. For this
data, the only outlier found was the maximum value of 39.28 Ohms.
Report – presenting evidence-supported argument
Presenting evidences to support an argument is a common function of professional communication. A good presentation of argument usually consists of the following
elements:
1. A clear declaration of the argument.
2. Clear citation of evidences.
3. Necessary discussion to link the evidence/reasoning to support the argument.
Requirements:
Based on your data analysis results, please write one paragraph to apply the Chauvenet’s criterion, and answer the following question. Please refer to the Uncertainty.pdf file
for the Chauvenet’s criterion and how to apply it.
• Are the minimum and the maximum calculated resistor values outliers?
Item
0 points
1 points
Paragraph spacing
The text is NOT double spaced.
The text is double spaced.
Text length
The text is either too short or too long.
The text is one paragraph of no more than 250 words.
Font
Non-standard font used for report.
Regular Times New Roman font of size 12 is used.
Math
Math symbols were not professionally typed in.
Math symbols were professionally typed using the built-in equation editor
of Microsoft Word.
Item
0 points
4 points
Declaration
An answer to the question is vaguely declared, or missing.
A clear and direct answer to the question is declared.
Evidence
Evidence is too weak to support argument.
Strong evidences (in the form of calculation and numerical values) from your
experiment results are cited.
Chauvenet’s criterion
Chauvenet’s criterion is not applied, or incorrectly applied.
Content
Chauvenet’s criterion is correctly applied to address the question.
Language
Informal language with more than 3 errors and awkward
content flow were used.
Don’t forget to attach a copy of this rubric to your lab report, otherwise 5 points will be marked down.
Formal language of natural content flow and with no errors were used
Professional Writing
In this lab, a total of 20 data points were taken to find the resistance value in an experiment. Once
all of the calculations were made, the statistics of the set were determined (average, standard deviation,
etc..), along with a maximum and minimum value. In order to determine an outlier, each data point was
evaluated using Chauvenet’s Criterion with the equation below:
𝑑𝑑𝑑𝑑𝑑𝑑𝑑𝑑𝑑𝑑 𝑑𝑑𝑑𝑑 𝑑ℎ𝑑 𝑑𝑑𝑑𝑑 =
|𝑑𝑑𝑑𝑑𝑑𝑑 − 𝑑𝑑𝑑𝑑𝑑𝑑𝑑|
𝑑𝑑𝑑𝑑𝑑𝑑𝑑𝑑 𝑑𝑑𝑑𝑑𝑑𝑑𝑑𝑑𝑑
After determining the deviations away, each value was compared to a table of given values of difference
and percent chances to occur, as shown below in Figure 1. Once the actual occurrence of each data point
was determined with the equation
𝑑𝑑𝑑𝑑𝑑𝑑 𝑑𝑑𝑑𝑑𝑑𝑑𝑑𝑑𝑑 =
# 𝑑𝑑 𝑑𝑑𝑑𝑑𝑑𝑑𝑑𝑑𝑑𝑑
× 100%
𝑑𝑑𝑑𝑑𝑑 𝑑𝑑𝑑𝑑𝑑𝑑 𝑑𝑑 𝑑𝑑𝑑𝑑 𝑑𝑑𝑑𝑑𝑑𝑑
The actual occurrence was compared to the chance to occur as given by the table based on distance from
the mean. According to this evaluation, there is one point that occurs more than the percent change to
occur, meaning there is one outlier in the data. This outlier is 39.28 ohms, which is the maximum value in
the data set, not the minimum.