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The slowly charging capacitor is the standard example used to illustrate that the displacement current is needed in Ampere’s Law if we want to correctly determine the magnetic field between the capacitor plates. However, it is not widely recognized that in any quasi-static situation the magnetic field can also be determined using the Biot-Savart Law with just real currents. In this presentation, we will see how including the effects of the surface currents on the plates helps explain the resulting magnetic field both between the plates and outside the plates. It is very likely that the results will surprise most viewers. Discussing these issues in an upper division physics course would provide students with additional physical insight into this interesting system.

AAPT SM 20

Untold secrets of the slowly charging capacitor

biot-savart

ampere

displacement current

capacitor

Join AAPT and Physics Educators worldwide in developing and strengthening your professional connections by attending the 2021 AAPT Virtual Summer Meeting. AAPT meetings are a great way to reflect on your teaching, recommit to best practices and re-energize your career with new research, products, and techniques.

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AAPT SM 21

technical paper

The 2020 AAPT Virtual Summer Meeting brought together physics educators from around the globe to learn about the latest in physics theory, research methodology and education from leaders in their field. The program featured plenary speakers, sessions, workshops and many special activities.

For more information please visit the 2020 AAPT Virtual Summer Meeting page at: https://www.aapt.org/Conferences/SM2020/index.cfm.


The 2020 AAPT Virtual Summer Meeting brought together physics educators from around the globe to learn about the latest in physics theory, research methodology and education from leaders in their field. 

Using matched PhysPort data, we assess the utility of plotting gains as a function of pre-test scores on the Force Concept Inventory (FCI). Doing so has the advantage of providing nuance regarding differences in populations, whether it be to shed light on the efficacy of instructional methods or equity among different student populations. We empirically compare raw and normalized gains and find for a population of 9,354 students that neither the raw nor the normalized gain is uniform for students of all pre-FCI scores. We suggest alternative methods for quantifying gain, the relative gain, and the relative raw gain, on standardized assessments that overcome this diculty. We compare the relative gain measures to effect size and nd that each contributes to our understanding of gains. The relative gain measures are straightforward to interpret and visualize. We suggest effect size and other gain measures, particularly the relative gain measures, be used in a complementary way to better assess the differences between populations.

Gains as a function of pre-test scores

Physics students enter into a broad range of careers. It can be challenging to know not just what kinds of positions physics majors can apply for but how physics students can find jobs that they are well suited for. This lighthearted talk will briefly provide data round undergraduate student employment but focus on how students can find and how advisers can help undergraduates apply for positions.

Careers for Undergraduate Physics Majors

Following the example in "Developing scientific decision making by structuring and supporting student agency" by N.G. Holmes, et al, students designed the research question in a three-week sequence and a written lab report was replaced with an online synchronous oral lab report, followed by time for questions from student colleagues. I will report on enhanced student engagement in class and in office hours and will share anecdotal comments. Students participated in a "belonging intervention". I will share practical lessons learned.

Giving students agency increased engagement at just the right time

Next Generation Physical Science and Everyday Thinking (Next Gen PET) – a research-based, guided-inquiry, physical science curriculum has been implemented at the University of Northern Iowa (UNI) in a required science course for elementary education majors since Fall 2016. We teach the studio version of Next Gen PET in 4 sections of the course each Fall and Spring Semester. Since Summer 2016, we have offered an on-line version of the course for 6 weeks to help meet demand for the course. In Spring 2020, the course transitioned from on-campus, in-person instruction to on-line instruction in March due to the outbreak of COVID-19. This presentation will share how we have transitioned to on-line instruction with Next Gen PET and include insights we have gained with comparisons made of going on-line by choice versus being forced due to COVID-19.

Transitioning to Online Instruction with Next Gen PET

Hands-on Minds-on Engagement through Remote Learning

Active learning has been shown to be more effective than passive lecture methods, but more work must be done to understand what mechanisms lead to effective active learning environments. The first step in understanding the mechanisms of active learning pedagogies is to establish a vocabulary with which to characterize them. One such method we have used is the Classroom Observation Protocol for Undergraduate STEM (COPUS), which codes student and instructor activities in two minute intervals. These profiles give us a picture of what kinds of activities are occurring in the classroom with the implementation of a given pedagogy. We have gathered COPUS profiles for six active learning pedagogies in physics. We discuss the individual characteristics for each pedagogy and present results from latent profile analyses.

Characterizing Active Learning Environments in Physics using COPUS

One argument for keeping the physics GRE is that it can help applicants who might otherwise be missed in the admissions process stand out. In this work, we evaluate whether this claim is supported by physics graduate school admissions decisions. We used admissions data from five PhD-granting physics departments over a 2-year period to see how the fraction of applicants admitted varied based on their physics GRE scores. We compared applicants with low GPAs to applicants with higher GPAs and applicants from large undergraduate universities to applicants from smaller undergraduate universities. We find that for applicants who might otherwise have been missed (e.g. have a low GPA or attended a small school) having a high physics GRE score did not seem to increase the applicant’s chances of being admitted to the schools. However, having a low physics GRE score seemed to penalize otherwise competitive applicants.

The Physics GRE does not help "overlooked" applicants

Modern wireless sensor technology coupled with integrated programming tools allow students to measure characteristics of the complex motion of falling chain systems and compare them to predictions created by their Blockly computer code. Because the data collection only takes a few seconds, this can easily be converted to a distance learning activity by providing students with the data files, software, and lab handouts. Programming techniques allow for accurate predictions to be made by introductory students about systems that would otherwise be too complex. We will look at the motion of a chain draped over a pulley and the force of a dropped chain striking the ground. The labs are appropriate for AP and introductory college physics classes. A link to student lab handouts, teacher guides, and sample data files will be provided.

Measuring and Modelling the Motion of a Chain

This session will dive into strategies to help promote a vibrant SPS chapter or club. Whether you are starting a new chapter, reviving a dormant chapter or wanting to explore opportunities to elevate your current chapter activities, this talk is for you. We will focus on the motivation and engagement of your students, and how to leverage resources from a local, regional and national level in efforts to help your SPS chapter flourish.

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Untold secrets of the slowly charging capacitor

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