1. Electric fields - from single charge to charged plates Mr Ang JL 27 Feb 2010

2. Creating the slides  Using the Java applet simulation from http://phet.colorado.edu/simulations/sims.php?sim=Charges_and_Fields http://phet.colorado.edu/simulations/sims.php?sim=Charges_and_Fields  The simulation allows the user to view the electric field around a charge or charges, and explore electric force on a positive test charge

3. Electric field of a single charge

4.  Two positive test charges are placed near it.  The arrows indicate the direction of the forces.  The length of the arrows indicate the strength of the force

5.  The small arrows around the positive charge represent the electric field Direction & Magnitude (the fainter the weaker the field)  Electric field is a vector A radial field

6. Electric field of a few charges

7.  For two neighbouring like charges, the fields “cancel” each other in the region between them, so it appears to be “horizontal”, instead of radial

8.  Bringing the two neighbouring like charges closer, the “canceling” effect become clearer.

9.  Adding more like charges, observe that the field “lines” are perpendicular to each row of like charges.  Near the ends of each row, the field is more radial

10.  Bringing the two rows of charges closer, does the field look like that for two charged plates?

11. A uniform field between two charged plates