# SAIP2012

9-13 July 2012
Africa/Johannesburg timezone
<a href="http://events.saip.org.za/internalPage.py?pageId=11&confId=14"><font color=#ff0000>SAIP2012 PROCEEDINGS AVAILABLE</font></a>

## The symmetry of Gauss’s law and Ampère’s law

11 Jul 2012, 08:00
20m
Oral Presentation Track E - Physics Education

### Speaker

Dr Ted Kroon (University of the Free State)

No

### Abstract content <br> &nbsp; (Max 300 words)

The correct application of Gauss’s law in electrostatics requires symmetry considerations which students often struggle with and which are often inadequately explained in textbooks. Ampere’s law in magnetostatics is the analogue of Gauss’s law, yet during its application symmetry arguments are seldom applied and other means are found to motivate the form of the magnetic field. A systematic approach for analyzing the symmetry necessary to apply Gauss’s law is first presented. Then, with the important consideration that the symmetry applies to the magnetic force rather than the magnetic field, this approach is used for analyzing the symmetry necessary to apply Ampere’s law. This strengthens the conceptual link between these two laws, but can also be used to introduce the interesting (but seldom discussed) idea that the magnetic field is an axial vector while the electric field is a polar vector.

References
1. C.A. Manogue, K. Browne, T. Dray and B. Edwards, “Why is Ampere’s law so hard? A look at middle-division physics”, Am. J. Phys. 74 (2006) 344–350.
2. D.A. de Wolf, “Ampère’s Law for a Linear Uniform Cylindrical Current”, IEEE Trans. on Education 50 (2007) 256–258.
3. J. Guisasola, J.M. Almudí, J. Salinas, K. Zuza and M Ceberio, “The Gauss and Ampere laws: different laws but similar difficulties for student learning”, Eur. J. Phys. 29 (2008) 1005–1016.

Yes

### Primary author

Dr Ted Kroon (University of the Free State)

 Paper