PREFACE TO THE INSTRUCTOR
These lab exercises are designed to reinforce and
deepen the knowledge of electricity and magnetism studied in the second
quarter of the physics with algebra sequence (i.e., physics 2b).
Due to a lack of appropriate equipment, the
electric is not explicitly studied. The labs begin with
measuring resistance. With no power source used in this first lab the
students (especially the inexperienced) will have the time to gain
confidence in using measuring equipment.
Since most 2B lectures do not start with DC
circuits, the theory expected of the students in the beginning labs is
kept to a minimum. The instructor may present these first labs from a
"phenomenological" point of view and leave the theory (e.g., voltage as
a difference in electric potential) for later. To the instructor who
finds the lack of Coulomb force and electric disturbing, it
is recomended that in-lab demonstrations be performed allowing the
students to play with the equipment afterwards while recording their
observations in their lab books. The well known electrostatics
demonstrations are available in the physics stockroom.
Only six labs are presented whereas the number of
lab meetings in a quarter is more. This allows for some labs to be
performed over a two week period, a neccessity in some cases if lab
books are not allowed out of the lab. As well, this allows for a
practical lab final administered during the last week of lab. The
"RESISTANCE AND VOLTAGE DROPS" and "THE OSCILLOSCOPE" labs almost
certainly will require two weeks to complete, but the E/M lab can
probably be done in one week. Please note that in the "CONSTRUCTING A
CAPACITOR" lab, wax paper and aluminum foil are required. These
materials are commonly found in supermarkets and the instructor will be
reimbursed from petty cash after the purchase. Please check with the
physics tech before starting this lab to make sure enough of these
materials are available.
The order of the labs may be changed by the
instructor, but it is necessary that all the labs be coordinated if
different instructors are teaching. Typically the lecturer is
considered the lab coordinator unless other arrangments are made. The
coordinator is responsible for giving a written schedule to the physics
tech of all the labs to be performed throughout the quarter one week
before the begining of the quarter. The lab structure as outlined in
the introduction below is merely a guide and may be violated if the
instructor provides a different method. The writing of a special report
during one of the lab periods is, of course, an optional exercise.
Often in this type of lab the skill of students can
vary tremendously. A teacher will commonly find students who have never
seen a resistor in the same lab with students who have been exposed to
circuits for many years. It is recommended that students paired as lab
partners be at the same skill level. For when students are partners at
greatly different levels, the more skilled becomes bored and the less
skilled becomes confused, not a good situation for either. Be cautious
having "experienced" students explain physical concepts to the
uninitiated; the "experienced" are often filled with misconceptions and
are eager to pass on their convoluted ideas to the naive.
Lastly, it is vitally important that the delicacy of
the equipment be made clear to the students. Particularly the Simpson
VOMs are subect to damage when measuring a voltage but dialed to the
resistance or the current scale. Please make sure the students are
aware of any possible way to damage the equipment they come in contact
with for the first time.