PHYS 401 :: Physics Illinois :: University of Illinois at Urbana-Champaign

Course Description

-- WORK IN PROGRESS --

Overview

Physics 401 is a one semester course intended to give students an introduction to basic laboratory techniques in experimental physics in the context of classical mechanics and electromagnetism.

In experimental physics we learn about the universe by asking it questions in a controlled way (experiment), and interpreting our observations quantitatively to constrain theoretical frameworks (analysis). In this course we will work through all aspects of this process at a level beyond that of your introductory courses:

We will use more complex laboratory equipment than you may be used to from introductory labs: oscilloscopes, digital multimeters, signal generators, lock-in amplifiers, Hall probes, etc.
We will focus more seriously on quantitative analysis in the presence of errors, including sources of error and noise, error propagation, basic statistics, and fitting models to data.
Effective written communication of your results will be key priority for this course.
We will introduce several foundational concepts not emphasized in introductory courses, notably Fourier domain signal analysis, synchronous detection, wave propagation in transmission lines, magnetic hysteresis, etc.

The tools and techniques we will use in this course are foundational to a wide variety of endeavors in science and engineering.

Course Objectives and Prerequisites

Through their work in this course, students will:

acquire basic concepts related to these experiments
become familiar with modern experimental instrumentation
learn how to make reliable measurements
understand the precision of a measurement and statistical analysis
learn how to do calculations with proper significant figures
learn how to do data and graphical analysis
learn how to write a laboratory report
learn how to approach an experiment systematically and think analytically

Note: The topics in this course depend upon an intermediate-level knowledge of both classical mechanics (Phys325) and E&M (Phys435). We now require 325 as a prerequisite and 435 as a corequisite for enrollment. The lab manual given with each lab is intended to present the necessary theoretical background to understand the experiment. If this is not sufficient, students are expected to learn the necessary material on their own using standard textbooks.

Course Components

The course consists of a one-hour lecture and a four-hour laboratory period each week.

LECTURE (Mon 3:30-4:20pm) is where we will discuss the concepts and history behind the week's experiment, outline the setup and equipment, discuss possible experimental challenges, and give tips for analysis and presentation.
LABORATORY (Tue/Wed/Thu, 4-hour blocks) is where you will work in pairs to carry out the experiments, record the results in your lab notebook, and carry out preliminary data analysis (so that you know if you need to fix anything!). You attend one lab section each week (at your registered time), and your TA will be there to provide guidances as needed. Some laboratories are completed in a single session, others require more than one week.
LAB REPORTS are where you describe your experimental work to the world. You introduce relevant background, describe your experimental methods, and discuss your main results and findings. Reports must be well-organized and clearly written, and are due one week after the lab is performed (one week after the final meeting of a multi-week lab).

Adapting to COVID-19

Teaching and learning during a global pandemic is challenging, particularly for a laboratory course. The ongoing pandemic has necessitated changes to the way we manage our course.

Our lectures this semester will be carried out online via Zoom. Lectures will be offered synchronously at the usual times, and recordings will be made available for those unable to attend at that time.
Our lab activities will also be online and synchronous. Adaptations will vary from activity to activity, ranging from simulation software (Multisim) to real-time control of laboratory equipment to video demonstrations. In cases where it is not feasible for everyone to acquire their own full data sets, you will be provided with data for analysis and lab writeups.
We will be expanding the lecture material on data analysis and other topics not common in introductory courses. We may add occasional short written assignments to go along with expansions of some topics - if so, we will warn you well in advance.
This spring campus has added three non-instructional "breather days" throughout the term. Lab sections will not meet during those weeks, and lab reports due those weeks will get a two-day extension for all sections.

Above all, I hope that all of us in Physics 401 -- students, faculty, and TAs -- can remember to show patience and kindness with one another. We're all muddling through this strange new era, and working to teach and learn physics in new ways. Some of us find ourselves working in unfamiliar contexts, and with unfamiliar constraints (my kids may burst in once in a while!).

Please don't hesitate to ask questions of Professor Filippini and the other course staff! I want to know if there are things that are not working or could be improved. My apologies in advance if the course procedures are in a little less final than normal for the first couple of weeks.

Course Topics

A. Instrumentation

Oscilloscopes
Digital multi-meters
Signal generators
Data acquisition hardware
Lock-in amplifiers
Power supplies

B. Data Analysis Software

Origin (WebStore)
Mathematica (WebStore)
For other options, see Computing Tools.

C. Data Analysis Techniques

Statistical error analysis
Fitting models to data
Time-domain analysis and transients
Frequency-domain analysis

D. Measurement Techniques

Measurements and modeling of systems that exhibit linear response
- Electrical: RLC circuits
- Mechanical: Torsional oscillator
Synchronous detection
Signal propagation in transmission lines
Measurement of the electronic charge
Measurement of magnetic fields
Response of magnetic materials to AC magnetic field

Course Grading

The primary graded course components are the laboratory reports for each activity. Due to the nature of this course, we cannot offer free "drops" of any lab report.

Lab Report Due Dates: Lab reports are generally due 1 week after the final lab session for that activity, at 11:59pm the night of your usual lab section meeting (Tuesday night for the Tuesday lab section, etc.).
- For the three weeks with "breather days" this semester, all groups get a two-day extension to usual due dates.
Turning in Lab Reports: Lab reports will be uploaded through the my.physics portal. We are also exploring the possibility of using other web tools.
Late Lab Reports: Lab reports turned in within 1 week after the initial due date will be penalized by 5% of the total score. Within 2 weeks, the penalty is 10%. After that, 25%.
Late Vouchers: Each student will have two vouchers to avoid the 1-week penalty. These cannot be used on the same report, nor after 1 week late, nor on the final report. You must inform your TA that you're using a voucher (preferably in advance!). Any unused vouchers will be credited for +5 points on your final course score.
Revise and Resubmit: You can revise one report and resubmit it for a regrade during the semester. The original report must be on-time or with voucher, and it must be a real report (fully completed, not an incomplete stub). Due date is the same as for the final report (which cannot be revised and resubmitted).

Course grading will proceed in compliance with University policy, as given in Article 3, Part 1 of the Student Code.

Your final grade for Physics 401 will be based upon your total score on all of the components of the course. The best possible score is 1160 points. Note that, due to the nature of this course, we cannot offer "free drops" of any activities. Tentative point assignments are as follows:

Course Component	Maximum Points
Labs	1000
RLC Transients	100
Synchronous Detection	100
Pulses in Transmission Lines	100
Counting Statistics and Data Analysis	100
Millikan Oil Drop	100
Torsional Oscillator	100
Hall Probe	100
AC Measurement of Magnetic Susceptibility	300
Written Activities	100
Problem Set 1	50
Problem Set 2	50
Lecture	60
T O T A L	1160