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

## Course Description

### 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.The lectures will provide information necessary to successfully complete the labs, as well as discuss applications of course material to current physics experiments and technology.**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).

### 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
- Studies with microwaves
- 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.).**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, reports are*not accepted*without prior arrangement and extraordinary circumstances.**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 have been a real report (fully completed, not an incomplete stub), and any non-voucher late penalties carry over. 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 |
---|---|

Lab Reports | 950 |

RLC Transients | 50 |

Synchronous Detection | 100 |

Pulses in Transmission Lines | 100 |

Millikan Oil Drop (2 weeks) | 100 |

Torsional Oscillator (2 weeks) | 150 |

Microwaves (2 weeks) | 150 |

AC Measurement of Magnetic Susceptibility (2 weeks) | 300 |

Supporting assignments | 90 |

Problem set: Error analysis | 40 |

Origin assignment | 50 |

Lectures | 60 |

T O T A L | 1100 |