University of Toronto s1

UNIVERSITY OF TORONTO

Department of Physics

Second Year Physics Laboratory

PHY225H

HOW IT ALL WORKS!

2002-2003

INTRODUCTION

The Second Year Laboratory is designed to extend the experimental skills you learned in the First Year Laboratory. Compared to that laboratory, you will find the typical experiment more complex and the apparatus more sophisticated. Specifically, in the Second Year Lab, we aim to have you improve your ability to:

·  solve problems in a hands-on context,

·  plan an experiment and design a procedure,

·  use laboratory instruments,

·  perform data analysis with appropriate error analysis,

·  keep complete records,

·  appreciate your equipment and what it is really measuring,

·  perform genuine exploratory work.

You will probably want to keep your copy of the First Year Physics Laboratory Manual from last year to refer to such parts as the Errors section. Students who did not do the First Year Laboratory on this campus should ask for a copy in room 229.

Even more than in the First Year Lab, we offer a wide variety of experiments; you are encouraged to choose those that most interest you. Unlike the First Year Lab, you will perform almost all the experiments on your own, without a partner. Only the experiment requiring four hands, "The Millikan Oil Drop Experiment", may be performed with a partner.

The relative sophistication of our experiments compared to the First Year Lab means that our experiments are even more `open ended'. (Experiment lengths are indicated by their weights rating.) The weights given in the experiment listings at the end of these notes are only `typical' values: the actual weight an experiment is worth depends on your choice, in consultation with the staff and demonstrators, of breadth versus depth in doing this laboratory.

WHO-WHAT-WHERE?

The people responsible for the running of this laboratory are:

Academic: Tetyana Antimirova 251A 946-4071

Nigel Edwards (coordinator) 509 978-2267

Technical: Howard Okada 123 946-8298

Tak Sato 250 978-0669

Phil Scolieri, Rob Smidrovskis,

Larry Avramidis 229/127 978-2957

In general, the technical staff provide information on apparatus and their specifications, in addition to maintaining and setting-up equipment, etc. The academic staff with the demonstrators (see photo gallery), provide information on experimental procedure and the underlying physics of the experiments, as well as all the other teaching functions that take place in the lab.

In addition to the First Year resource centre in Room 126, the Second Year Laboratory has its own resource centre located in Room 229. This centre will always be staffed during scheduled laboratory hours and is the first place to look for a piece of equipment. The resource centre also contains a small library of particular relevance to this laboratory, which is a supplement to the larger library in Room 126 and the Departmental library on the second floor of the Burton tower. These libraries will be important to you as most experiment guide sheets assume that you have gone to other references to work out the significance and details of the experiment.

The laboratories themselves occupy 12 rooms located in the North-East area of the second floor of the McLennan Building. The main lab room is 235. Next to Room 235 is a foyer (Room 234) that houses the Guide Sheets for the available experiments and the shelves on which you will keep your lab notebook. In the hall immediately outside Room 235 is a series of notice boards; you are expected to be familiar with the contents of these boards.

LAB PROCEDURES

In the Second Year Lab you will have your own demonstrator to whom you will continue to report throughout the year. You will be assigned to a lab group under the supervision of that demonstrator, who will be your group leader and who will monitor your progress throughout the year. However, since the experiments are more challenging than the typical offering in the First Year Laboratory we particularly cannot expect a single demonstrator to be responsible for all the experiments her/his students may perform during the year. Thus, responsibility for individual experiments is divided among the demonstrators, who will serve as your primary resource for that experiment and who will mark your work when you have completed it.

Your group leader:

·  Keeps track of your general progress throughout the year,

·  Books the experiments you wish to do,

·  Keeps track of all the marks you receive from the experiment demonstrators,

·  Provides the overall assessment of your laboratory work,

·  Supervises and evaluates four of the "exercises" you do,

·  Marks your Formal Report.

The experiment demonstrator (responsible for specific experiments):

·  Supervises and evaluates your performance on the experiment,

·  Signs, with you, your contract to do the experiment.

·  Briefs you on the ideas, concepts and details of the experiment,

·  Passes the mark you receive on her/his experiment to the group leader.

The laboratory is designed so that its requirements can be largely completed during scheduled hours. The normal lab hours are 9 am to 12 noon every Thursday. It is only during these hours that we can guarantee the accessability of the laboratory staff for questions. Thus attendance during your scheduled laboratory is important and required. You must check in with the experiment demonstrator for the experiment you are performing every time you come to the laboratory. . You may only work in the lab "off hours" with explicit permission to do extra work, but this is not a substitute for your presence during scheduled hours.

It is generally expected that you will do all writing of experiment descriptions, observations and interpretations in your lab notebook while in the lab. Thus you will normally not take your lab notebook home. There are shelves in room 234 on which your lab notebook will normally be kept. If you do need to remove the books for some extra calculations at home, you may do so.

It is important that you receive regular feedback on your performance throughout the year. Thus, when you complete an experiment or exercise, you must:

·  Inform your group leader, who will discuss with you the next experiment or exercise you will do and will move your tag on the booking board, thus freeing the previous apparatus for other students and reserving a new apparatus. Note, you may begin work on your next experiment in the middle of a laboratory period. If you complete an experiment at the end of a lab period, book your new experiment then; don't wait till the next class to book.

·  Leave your lab book with the experiment demonstrator for the old experiment, to be marked when you leave the laboratory that day. It will be marked and available on the shelves in room 234 at your next scheduled laboratory. (If it isn't marked by then, you have a right to complain about slow service.)

·  Go to the experiment demonstrator for the new experiment and sign a contract form.

Note that an experiment is considered complete, only when the write-up is done and the work is ready to be marked. Your group leader is instructed to refuse to allow you to continue work on an experiment when a previous completed one has not been submitted for marking. (In other words, you are not permitted to be working on more than one experiment at a time.)

LAB REQUIREMENTS

EXPERIMENTS: In this lab, any one of a number of experiments could be profitably pursued for the entire year. However, most students find that eventually they have discovered enough physics with a particular apparatus, and wish to move on. You are encouraged to decide, in discussion with your group leader, whether you wish to do this laboratory course by performing a greater number of experiments at a more superficial level or a fewer number in greater depth. The weights ratings given to experiments in the last section of these notes should help to guide you as to the depth of experimentation typically carried out by students in this laboratory. (Recall that a weight is roughly the number of three hour lab sessions needed to perform the experiment to this `typical' level.) The actual weight you receive for a particular experiment is a matter for discussion with the demonstrator responsible for the experiment. Your first experiment will be of a one or two weight length. Later experiments may be longer. In selecting your experiments and weights as well as when planning your experiment, you should manage your time carefully. With the many tasks to perform in the lab, it is all too easy to spend many more hours than scheduled  something to be avoided.!

Evaluation of experiments will be done by the demonstrator responsible for the individual experiment. For most of your experiments, you will be evaluated using a mix of in-lab assessment and lab notebook examination. For some of your experiments, a short oral interview may form some or all the basis of evaluation.

EXERCISES: You are required to complete various exercises early in the year. These exercises are intended to insure that you possess the range of experimental techniques we feel are necessary for experimental physics at this level. They will be marked ``pass'' or ``incomplete'' (no number grade assigned) by your group leader, and you must pass all required exercises by the end of the fall term. Each exercise takes one lab session to perform. The exercises are listed below. You will not necessarily do the exercises in the order in which they are listed.

Exercise 1 Orders of magnitude

Exercise 2 Vacuum system

Exercise 3 Thermocouple

Exercise 4 Index of Refraction

Exercise 5 Computer interface to experiment

FORMAL REPORT: You will write and submit a formal lab report in journal style format. The formal report is due at your last laboratory before reading week in the spring term. The formal report serves primarily as a writing exercise and will be marked by your group leader. It will be based on an experiment you have completed. Your group leader will assign which experiment you report on. (See the section on formal report writing below.)

ORAL EXAM: At the end of the academic year, you will stand an Oral Exam conducted by the laboratory academic staff. This test will examine one or two of the experiments you have performed during the year. You will be asked about experimental and theoretical aspects of the experiments. The choice of what experiment will be made by the examiners at the time of the test.

WORKSHOP PRESENTATION: In the Spring term, you will work in groups of 2 to 4 people researching a topic in current experimental physics. A list of possible topics will be made available, but you may choose another topic in consultation with the laboratory staff. You will present the results of your investigations in two ways:

·  An oral presentation to your classmates and laboratory staff.

·  A written report to the laboratory academic staff.

During the period when oral presentations are being given the regular laboratory is closed, and attendance at all presentations is required.

LECTURE: There is a one hour lecture on topics in experimental Physics each week. Attendance is required. The lectures take place at 12 noon on Thursdays in room 134.

INTRODUCTION TO MACHINING: During the spring term you will have the opportunity to learn basic machine shop skills. You may attend 4 one-hour sessions. Attendance is optional.

MARKING SCHEME: The marking scheme for PHY225Y is shown below.

LAB NOTEBOOKS - What you write and when

The keeping of lab records by students in the Second Year Lab is part of your training for your later scientific life. We thus expect that your notebook will resemble that of a professional scientist. The following is an attempt to clarify our lab notebook expectations.

WHAT THE NOTEBOOK IS FOR:

The notebook provides both a structure for recording your experimental work and a record of that work. Actual, unprocessed records and subsequent calculations made during data collection are saved. In a research company, the records are also legal records. In court proceedings, the dated, original lab notes may the critical evidence in a patent dispute.

WHEN ENTRIES ARE MADE IN THE NOTEBOOK:

Whenever you do any work on an experiment, you should be making entries in the notebook. Your notebook is a diary, and so entries are made in chronological order. These entries should all be dated. Notebook entries start with jottings on your preliminary background reading and investigation, progress through records of your experimental set-up, include data (which are both numbers and narrative) and calculations, and end in evaluations and conclusions. All these entries must be made simultaneously with the actions they describe. Indications of idiosyncrasies in the apparatus must be written at the time the idiosyncrasies are observed, not two weeks later.

WHAT SHOULD BE ENTERED IN YOUR LAB NOTEBOOK:

·  Dates and times liberally spread throughout the data/figures/narratives.

·  Sketches of important details of apparatus. In most cases, schematic representations are preferable to pictorial detail. This is particularly relevant to electrical circuits.

·  Data  numbers, comments and descriptions  systematically entered (in tabular form where possible). All the data should be there, including the data that failed (with annotation of why it failed). In particular, all anomalies and surprises and your reactions to them should be included. Note that error estimates are part of your data.