Lab Manual Errata
This particular page contains the various errata that needs to be added to the next printing of the lab manuals. When an error is spotted, please place it in the proper lab section, referencing which experiment needs to have the changes applied to it, as well what changes will be made and why.
103 Lab
104 Lab
Page E1-5:
1. "...when the acrylic rod..." 2. "..., the acrylic rod charges positive..." (ZD)
Lab E1 (in general):
have the students notice that when the charged rods got closer to the Faraday cup the voltage reading got larger. Hence the electric potential decreases with distance. Also, charge a rod and bring it to a certain distance from the Faraday cup. Charge the rod some more and repeat. Thus we know electric potential grows with charge. Maybe drop questions 5-8 and add those to illustrate what they're learning in class. (IL)
add specific instructions how to discharge the rods. (IL)
Page E2-5:
expunge references to 15V, and replace with reference to 24V, changing steps in paragraph 7 to 0V, 6V, 9V, 12V, 15V, 18V, and 21V. (ZD)
For Lab E-3, in problem 2 the exploration should direct the students to measure the current through each resistor in parallel (there's a question in the analysis about this.) If we could add a diagram to the lab notebook I have good setup for measuring the currents. Also, the diagrams on page E-3 4 and E-3 7 can be confusing for the setup.
Also, when the exploration asks the students to "Calculate the equivalent resistance" for the parallel and series circuits, its not clear that what they should be calculating
(total potential difference across circuit)/(total current through circuit)
and comparing to pre-lab question answers for equivalent resistances for parallel and series resistors.
Also, the analysis asks "What simple fraction of 8V falls across each resistor when they are in series" The fraction isn't simple, but it can be compared to (individual resistance)/(equivalent resistance). For parallel we should compare (individual current)/(total current) to (equivalent resistance)/(individual resistance).
Finally, there seems to be inconsistencies labelling "Pre-lab Questions" and "Method Questions" and the students are confused about whether they's supposed to be doing both. (IL)
109 Lab
201 Lab
202 Lab
207 Lab