Electricity and Magnetism slp

 

For this module you will run a simulation of Lorentz force exerted on a current carrying conductor located in the magnetic field of a horseshoe magnet.  The experiment is set up so that you can change the direction of polarity of the magnet and the direction of the current as well as turn the current on and off.

Click on the following link, listed in the Background Materials,  to access the simulation

Fendt, W.  (1999).  Lorentz force (simulation).  Retrieved on 13 Nov 07 fromhttp://www.sciencejoywagon.com/physicszone/otherpub/wfendt/lorentzforce.htm

In the simulation, the electrical current flows from positive (+) to negative (-). Notice that the current flows into the screen when the current source is on the left,  and out of the screen when the current source is on the right.  Change the direction of the current by clicking the “reverse current” button.

The lines of magnetic force flow from north (red) to south (green).  You can flip the magnet vertically and change the direction of the magnetic field 180 degrees by clicking the “turn magnet” button. 

In response to the magnetic field, the wire carrying the current is displaced either to left, or to the right. 

Complete the following table.  The first line has been filled in for you.

 

Current Direction		Magnetic Field Direction		Wire Displacement
Into screen		Top to bottom		Left
Into screen		Bottom to top
Out of screen		Top to bottom
Out of screen		Bottom to top

 Write a one to two page paper summarizing the results of your experiment, and discussing these results in terms of what you have learned about the Lorentz force and the behavior of current carrying conductors placed in a magnetic field.

 

Note: URL verified on June 10, 2012. If an assignment requires that you include a source in a reference list, then you should verify that the source is still available, and enter the date you performed the verification.

Most of the problems in the module have to do with Coulomb’s Law.  For excellent discussions, see CK12 (2011a), Nave (2010) and Khan (2011).  The Kahn reference is one of large number of short, to-the-point lectures on a huge number of topics.  Take the time to browse around Khan Academy!  

Khan (2011) and the CK-12 Foundation (2011) provide tutorlals on the topics covered in this module, and much else besides.

Wolfram Research (2007)  is an excellent overview of electromagnetism.  The other sources continue the discussion, and also contain interesting simulations.  

As always, feel free to surf the Web for additional information.

Required Materials

Fendt, W. (1999). Lorentz force (simulation). Retrieved <Date: See note above> fromhttp://www.sciencejoywagon.com/physicszone/otherpub/wfendt/lorentzforce.htm

Fendt, W. (2003). Magnetic field of a bar magnet (simulation). Retrieved <Date: See note above> from http://www.walter-fendt.de/ph14e/mfbar.htm

Fendt, W. (2003). Magnetic field of straight current-carrying wire (simulation). Retrieved <Date: See note above> fromhttp://www.walter-fendt.de/ph14e/mfwire.htm

HowStuffWorks, Inc. (2007). How electric motors work. Retrieved <Date: See note above> fromhttp://electronics.howstuffworks.com/motor.htm

Université Laval (Canada). (1996) Exploring electric fields (Java simulation). Retrieved <Date: See note above> fromhttp://www.gel.ulaval.ca/~mbusque/elec/main_e.html

Wolfram Research (2007). Eric Weisstein’s world of physics – Electromagnetism. Retrieved <Date: See note above> fromhttp://scienceworld.wolfram.com/physics/topics/Electromagnetism.html