On Saturday, December 13, at Clayton High School, the St. Louis Area Physics Teachers will reprise a workshop originally designed and led by Mark Schober many years ago. The theme of this workshop is magnetism experiments and demonstrations.
Participants will use homemade equipment, some designed by Mark Schober and some designed by Rex Rice, to perform several experiments and demonstrations. The majority of the experiments/demos are about magnetism, but the equipment can also be used for a qualitative electric field mapping experiment which we will also perform.
In this workshop, participants will gain experience with the equipment with the hopes that they will have a better idea of whether or not they would like to build some of the equipment at a followup workshop on Saturday, January 10.
The experiments and demonstrations that we will perform include:
- Magnetic force on a beam of electrons (demonstration)
- Magnetic force on a current carrying wire (demonstration)
- Magnetic force between two wires carrying current in the same direction (demonstration)
- Magnetic force between two wires carrying current in opposite directions (demonstration)
- Magnetic field strength vs. distance for a bar magnet (experiment)
- Magnetic field strength around a straight, current carrying wire, magnetic field strength vs. current (experiment)
- Magnetic field strength around a straight, current carrying wire, magnetic field strength vs. distance from wire (experiment)
- Tangent galvanometer--magnetic field strength inside of a coil of current carrying wire vs. current (experiment)
- Tangent galvanometer--magnetic field strength inside of a loop of current carrying wire vs. number of loops (experiment)
- Current Balance--Magnetic force vs. current (experiment)
- Current Balance--Magnetic force vs. length of wire (experiment)
- Current Balance--Magnetic force vs. magnetic field strength (experiment)
- Qualitative electric field mapping (experiment)
- Quantitative electric field mapping. I'll show you the equipment and describe this experiment, but we won't actually perform this experiment during the workshop.
You'll get to use equipment like the equipment that you'll build during the January 10th workshop during these demonstrations and experiments. I plan to have approximate costs associated with building the apparatus for these experiments at the December 12 workshop. We'll take orders for the equipment at this workshop, order and precut some of the parts between December 13 and January 10, and then build the equipment on January 10.
You will be welcome to order equipment sets if you are not able to attend the December 12 workshop, but we will NOT be performing the experiments again on January 10. You may also order parts kits if you aren't able to attend the January 10 workshop, but you will have to pick up the parts kits from Clayton High School and put them together yourself.
We will expect payment for the parts within one week of the December 13 workshop so that we can order them in time for the workshop.
Several people have volunteered to help precut some of the parts in order to make the January 10 workshop more efficient. We haven't yet scheduled a time for that activity, but if you'd like to be a part of that, contact Rex.
It would be very helpful if people would RSVP with me (rexrice@claytonschools.net) so that I know how much equipment to set up on Saturday, December 13. I'd like to keep the lab groups to 2 or 3 people per setup.
In addition to the apparatus that you will be building, certain other equipment will need to be available for you to perform the experiments/demonstrations. Demo 1 requires a CRT based oscilloscope. Demo 2 and experiments 2 through 12 require a DC power supply capable of at least 3 amperes, but preferably 5 amperes or more. Demo 4 requires even more current--a car battery works really well. Experiments 5-9 require a decent liquid filled magnetic compass or a magnetic field sensor such as the version that Vernier sells. http://www.vernier.com/products/sensors/mg-bta/. I'm certain that the apparatus could be modified to work with the Pasco magnetic field sensor as well, but I don't have Pasco interfaces, software, or probes to try out at the workshop. If you do and want to try them with this equipment, feel free to bring the probe, interface, and a laptop with the necessary software installed to the workshop.
Experiments 10, 11, and 12 required a digital scale with at least 0.01 g resolution and at least 100 g capacity.
We'll have both the magnetic compass and the magnetic field sensors versions of the experiment for people to use.
Even if you don't have the necessary equipment to go with the make and take items, you might want to participate in the December 13 workshop to learn about the labs and equipment and the January 10 workshop to build the equipment for a later time when you might acquired the necessary other equipment.
These demonstrations and experiments are appropriate for all physics courses in which magnetism is studied, and would be excellent for AP Physics 2 or AP Physics C E & M courses.
Rex Rice
Physics Teacher
Clayton High School