Spring 2011
Physics
401 is a one semester course intended to give students an introduction to basic
laboratory techniques in the context of classical mechanics and
electromagnetism. The course consists of a one-hour lecture and a 4-hour
lab-period per week.
The
primary goal of the course is to introduce students to basic concepts in
experimental physics including:
Ø
acquire
basic concepts related to the experiments
Ø become
familiar with modern experimental instrumentation
Ø learn how to
make reliable measurements
Ø understand the
precision of a measurement
Ø learn how to
do calculations with proper significant figures
Ø learn how to
do data and graphical analysis
Ø learn how to
write a laboratory report
Ø learn the
advantages and limitations of computers in experiments
Ø learn how to approach an experiment systematically and think analytically.
Note: Although only P325 is required for the course, most of
the topics require background in E&M. The lab manual given with each lab
does 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 (see Griffiths’ excellent E&M text).
The
topics covered include:
A.
Instrumentation
1.
Oscilloscopes
2.
Digital multi-meters
3.
Signal generators
4.
Data acquisition hardware
5.
Synchronous detection using lock-in amplifiers
B.
Data Analysis/Acquisition Software
1.
Origin
2.
Mathematica
C.
Data Analysis Techniques
1.
Statistical and error analysis
2.
Frequency and time domain analysis
D.
Measurements
The
experiments are intended to cover a diverse set of topics including:
1.
Measurements of systems that exhibit linear response
i.
RLC circuits
ii.
Torsional oscillator
2.
Time and frequency domain measurements
i.
Fourier analysis of pulses
ii.
Pulses in transmission lines
3.
Electromagnetic Phenomena
i.
Measurement of electronic charge
ii.
Measurement of magnetic fields
iii.
Studies with microwaves
iv.
Response of magnetic materials to time-varying fields
·
Computers on 2nd floor of LLP have Mathematica, Origin, Matlab, MS office, LaTex, etc.
· OriginPro 8 is available at the UIUC Webstore for free.
|
|
Name |
Office Hours |
Phone |
e-mail |
|
Lecturer |
Prof.
Benjamin Lev |
Mondays 2-3 pm
in |
Office: 333-8079 |
|
|
Laboratory
Instructor |
Mr. Matt Stupca |
|
|
|
|
Laboratory
Instructor |
Mr. Di Li |
|
|
|
|
Laboratory
Instructor |
Mr. Tuan Hoang |
|
|
|
|
Laboratory
Technician |
Dr. Jack Boparai |
None |
office:
333-2208 |
|
|
Technical
Assistant |
Prof. Eugene Colla
LSI 290A |
None |
office:
333-5772 |
LLP = Loomis Laboratory of Physics LSI = Loomis-Seitz
Interpass ESB =
Engineering Science Building MRL
= Frederick Seitz Materials Research Laboratory
·
You will have one lab partner for each experiment. You are
expected to rotate partners for every new experiment.
·
All of your reports are individually written. You are
encouraged to share data with your partner and discuss the lab, however, the
individual reports must be your own work (we will notice).
Consult with your instructors for any
problems regarding your reports, laboratory schedule, etc. You may email, call
and/or drop in to resolve your problems as soon as possible.
Excused absences follow the same criteria as
Physics 211 excused absences. All the lab sessions are full, but in extreme cases it may
be possible to triple-up, with permission of the
instructor and the lab TA.
Lecture Notes and Course
Gradebook
Report Structure
All reports should be prepared using a word processor. Refer to
the report preparation guideline for instructions on how to prepare your
reports. Click here to
download guideline.
You will receive 5 extra points per report that is written using
LaTeX (excluding the midterm paper and final lab report), the typesetting program used for nearly all physics journal papers. (See LaTeX wiki, for example.)
Here are helpful websites:
LaTeX homepage: http://www.latex-project.org/
LaTeX in Windows: http://miktex.org/, http://www.texniccenter.org/
LaTeX in Mac: http://www.tug.org/mactex/2009/, http://www.uoregon.edu/~koch/texshop/
Cross platform editors: http://www.lyx.org/, http://www.xm1math.net/texmaker/
"Not So Short Introduction to Latex": http://tobi.oetiker.ch/lshort/lshort.pdf
|
|
Day |
Instructor |
Time |
Room |
|
Lecture |
Monday |
Prof.
Benjamin Lev |
3 - 3:50 PM
|
158
|
|
Section
L1 |
Tuesday |
Mr. Matt Stupca |
1:00 - 4:50
PM |
ESB
6103 |
|
Section
L2 |
Wednesday |
Mr. Di Li |
1:00 - 4:50
PM |
ESB
6103 |
|
Section
L3 |
Thursday |
Mr. Tuan Hoang |
1:00 -
4:50 AM
|
ESB
6103 |
|
Week of |
No. Weeks |
Lab Title |
Point Value |
|
Jan. 17
|
--- |
No lecture Monday (Martin Luther King day); No labs this week. Read Error
Analysis Part I- download
Laboratory
Notebook and Reports Style Manual for Physics 401 - download
Sample Report - download Review this website on curve fitting
|
--- |
|
Jan. 24
|
---
|
Lecture and Labs will be held at normally scheduled times Introduction
to oscilloscope, function generator, digital multi-meter (DMM), and curve fitting- download
Error
Analysis Part I- download
Laboratory
Notebook and Reports Style Manual for Physics 401 - download
Sample Report - download Review this website on curve fitting
|
---
|
|
Jan. 31
|
1
|
Transients
in RLC circuits - download
|
50
|
|
Feb. 7
|
1
|
Frequency
domain analysis of linear circuits using synchronous detection - download
RLC lab report and lab book due at begining of lab section |
100
|
|
Feb. 14 |
1
|
Pulses in
transmission lines - download
Freq analysis lab report and lab book due at begining of lab section |
100
|
|
Feb. 21 |
1
of 2
|
Millikan Oil
Drop Experiment / Week 1 - download
Transmission lines lab report and lab book due at begining of lab section |
---
|
|
Feb. 28
|
2
of 2
|
No lecture this week. Millikan Oil
Drop Experiment / Week 2
|
100
|
|
Mar. 7
|
1
of 2
|
There is a lecture this week. No lab report for Torsion Oscillator, but lab book will be graded Torsion
Oscillator / Week 1 - download
Millikan oil drop lab report and lab book due at begining of lab section |
---
|
|
Mar. 14
|
2
of 2
|
No lecture this week Torsion
Oscillator / Week 2
Catch-up on reading, lab reports, and write midterm paper |
100
|
|
Mar. 21
|
---
|
Spring break week: No lecture or lab
|
--- |
|
Mar. 28
|
|
Hall Probe
Measurement of Magnetic Fields-download
Mathematica
workbook - download
Torsion oscillator lab book due at begining of lab section Midterm paper due at begining of lecture on monday (no late papers accepted---cannot use voucher on this) |
100 |
|
April 4
|
1
of 2
|
Qualitative
Studies with Microwaves / Week 1
Hall probe lab report and lab book due at begining of lab section |
---
|
|
April 11
|
2
of 2
|
No lecture Microwave
Cavities / Week 2 - download
|
150
|
|
April 18
|
1 of 2 |
No lecture, but Lev Lab tour instead of lecture Final
Project – AC Measurement of Magnetic Susceptibility / Week 1 – download
Craik
– download
SR830
Manual - download
Microwave lab report and lab book due at begining of lab section |
|
|
April 25
|
2
of 2
|
No lecture Final
Project – AC Measurement of Magnetic Susceptibility / Week 2
|
300 |
|
May 2
|
--- |
(No lecture or labs) Thursday
May 5 – Reading Day (late reports except final project are due today)
Final exams:
Friday May 6 – Friday May 13
|
|
|
May 9
|
--- |
Final
Projects Due at 1:30 pm Wednesday May 11th
in Loomis
337
|
Total 1150
|
This is a short discussion on error
analysis. It, along with subsequent lecture notes, will provide information on how to analyze your
data. There are excellent discussions of expressing uncertainty by NIST as well as
on statistics
and probability
from LBL. There are no course textbooks, but we recommend buying or checking out of the library An Introduction to Error Analysis
Laboratory report guide:
This short and concise note discusses how to
write your report and some explanation of error propagation.
Frequency and Time Domain Analysis RLC Circuits and Transmission Lines
Part I:
Frequency Domain Spectroscopy
Understanding the frequency response of
physical systems ranging from single atoms to complex condensed matter systems,
e.g. metals, insulators, superconductors and ferromagnets, is essential to understanding
the physics of the underlying interactions. In this lab we will learn about two
widely used techniques for the characterizing frequency response, (1) frequency
domain (FD) spectroscopy and (2) time domain (TD) spectroscopy. The techniques
will be applied to characterize the frequency response of simple linear
circuits. In part I of the lab, you will investigate the dynamics of resonant
RLC circuits and RC filters using lock-in detection.
Part II:
Time Domain Spectroscopy
In part II of the lab, you will apply time
domain (TD) analysis of complex impedance and compare your findings with FD
measurement.
Measurement of the electronic
charge by the "Millikan" oil drop method
One of the most important physical
quantities is the magnitude of the electronic charge, e. The first precision
measurement of the value of e was accomplished by the American physicist,
Robert A. Millikan (1868-1953), who in 1911 reported the results of his oil
drop experiment, done at the University of Chicago. In this experiment, we will
repeat this Noble prize winning experiment within two lab sessions. A charged
oil drop is introduced between two oppositely charged horizontal plates where
its velocity of fall under gravity and its velocity of rise in response to a
suitable electric field are measured. From this data, the charge on the droplet
may be calculated. In order to speed up the measurements, the computer measures
the time and records the data in a spreadsheet file. The data then may be
analyzed in Excel. We have new setups as of Fall 2006! For
reference, we also have a copy of the PASCO manual that came with the
equipment.
The Torsional Oscillator
This is a two week lab to study the
transient and driven response of a torsional oscillator.
During the first week, you will investigate
(1) the transient solutions of a mechanical oscillator; and (2) other forms of
dissipation besides viscous damping or the linear form found in RLC circuits.
This experiment will reinforces the concepts from Transients in RLC Circuits. Although, in general, it is more
difficult to carry out a mechanical study of resonance, there are several
advantages. The motion can be directly observed and studied. There is no need
for an oscilloscope. Changes in mass, moment of inertia or spring constant are
more obvious than changes in inductance or capacitance. Phase shifts can be
seen. Different forms of dissipation can be created and studied. In addition to
magnetic damping, which is like the effect of an electrical resistance in an
RLC circuit, Coulomb (or dry) friction occurs in mechanical systems. The
magnitude of Coulomb friction is independent of velocity. Also, turbulent
dissipation can be studied. Turbulent friction is found in the motion of air
around a fast moving car or in the motion of water around a boat. Such
dissipation can increase as the square (or larger) power of speed.
In the second week, you will study both the
transient and steady state behavior of a driven harmonic oscillator.
Understanding the driven harmonic oscillator is the way to understand many
physical systems. The same basic equations apply to electrical circuits,
optical absorption, and even the stability of your car. The associated
phenomenon of resonance provides a valuable tool for physical measurements. By
studying the resonant frequency, line width, strength, phase, and line shape of
a resonance we can carry out precise measurements of the motion of a nucleus of
an atom (Nuclear Magnetic Resonance) or the stability of a space ship. The
driven torsional oscillator can demonstrate all these characteristics in a
quantitative fashion. There are several phenomena that can be measured during a
limited amount of lab time such as phase and line shape as well as transient
"beats" and the steady state response as a function of frequency
using viscous, magnetic damping.
Experiment 67: Hall Probe
Measurement of Magnetic Fields
Whereas no convenient technique exists for
measuring arbitrary electric fields , several techniques are available for the
practical measurement of magnetic fields . These include the observation of the
force exerted on a current-carrying wire, the emf induced in a rotating coil,
the frequency at which certain atomic or nuclear systems exhibit resonant
absorption, and the Hall voltage induced in a current-carrying conductor. The
latter technique utilizing the Hall effect has the advantages of requiring only
a very small probe and very simple instrumentation. During this laboratory, you
will become acquainted with the characteristics of the Hall probe. A gaussmeter
is an instrument that is designed to measure the magnetic field using a Hall
probe. At the later part of this experiment, you will use a commercial
gaussmeter to study the magnetic field distributions produced by both a
Helmholtz coil and a solenoid.
As part of this experiment you will
use a Hall probe to map out the field configuration from distributed current
sources as well as from arrangement of permanent magnets.
Part II:
In this section, you will construct and measure the field for several Halbach
magnet geometries. The description of the measurement is given here.
There is a Mathematica notebook to assist you in the field calculations. Click here
to download the Mathematica notebook. In addition, I have included a reference
that discusses Halbach magnet geometries. Click here for the reference.
Study of Electromagnetic Wave Phenomena Using
Microwaves
Part I:
Experiment 34: Qualitative Studies of Microwaves
The purpose of a set of 6 experiments is to
acquaint the student with the properties of electromagnetic waves. These 6 set
of experiments are : (1) wavelength measurement; (2) standing waves
measurement; (3) polarization; (4) microwave Michelson interferometer; (5)
total internal reflection; (6) Bragg diffraction. Microwaves are well suited
for this purpose because the wavelength and the dimensions of the apparatus are
convenient for bench use. Properties of the radiation, such as its polarization
and its reflection by various materials, can also be demonstrated directly and
simply. The lab setup is based on the Lectronic Research Labs Microwave
Training Kit . This kit provides a convenient source of microwaves with a
wavelength of about 3.5 cm.
Experiment 44: Microwave Cavities
The purpose of this experiment is to
investigate the various properties of a rectangular microwave cavity. A 3-cm
low power microwaves are used (1) to measure wavelength of the microwaves using
a slotted line, (2) to determine the cavity resonances, (3) to investigate the
magnetic field direction and coupling inside the cavity, (4) to study the
nature of the electric field distribution inside the cavity, and, (5) to
determine the cavity quality factor Q.
Final Project – AC Measurement of Magnetic Susceptibility
Supporting Material: SR830 Manual, Magnetism-Craik, Magnetic Properties Data Sheets
Transients in RLC Circuit
Powerpoint slides of a Physics 112 lecture
on complex impedance in AC circuits written by
Professor James N. Eckstein of our department.
Physics 112 Complex
Impedance Lecture
Transmission line
Simulation of signal at load and reflected signal
from various terminations used in the transmission line experiment.
Fourier Analysis
Excel workbooks on the Fourier decomposition
of a square wave and a triangle
wave written by Professor Steve Errede of out department.
Practical guide to the Excel FFT function
including a discussion of its normalization and an Excel file showing the FFT
of the free decay of the damped oscillator and pure sine waves.
Excel worksheet to accompany the guide to the
Excel FFT function.
The Fourier transforms of a symmetric
triangle wave and a 50% duty factor square wave have no even harmonics. The
reason is often misunderstood. Why
no even harmonics discusses this point.
References on the discrete Fourier transform may be found at the end of the FFT wiki. Or see The Fast Fourier Transform by Brighman, Prentice Hall, 1974.
Millikan Oil Drop
Note on error analysis in Millikan oil drop
experiment
Error
analysis for Millikan oil drop experiment
Excel templates for analysis of Millikan oil
drop experiment.
Rise
and fall time analysis for Millikan oil drop experiment
Charge
quantization and magnitude analysis for Millikan oil drop experiment
Torsional Oscillator
Powerpoint slides of fall, 2000 Physics 225
lectures on damped, driven harmonic oscillator, Fourier
analysis, and impulse response methods written by Professor James E.
Wiss of our department.
Physics
325 Damped Harmonic Oscillator Lecture
Physics
325 Damped, Driven Harmonic Oscillator Lecture
Physics 325 Periodic Driving Forces Lecture
Physics
325 Impulse Methods Lecture
Powerpoint
slides showing various equivalent definitions of the Q of an oscillator
Information
about the server, Phyaplportal, and Netfiles is here.