Electric Field Viewer is divided into three screens. That screen on the left is the viewscreen where information about the electric field will be visually displayed. At the top right is a control screen, where various aspects of the simulator can be manipulated. At the bottom left is the display screen, which displays numeric information about the electric field.
On the control screen, there are four controls.
The menu at the top, labeled "# of Charges," controls the number of charges in the electric field.
"Positive charge(s)" yields only positive charges.
"1 negative charge" yields a negative
"Mixed charges" gives a combination of the two.
The menu labeled "Background" lets you control the viewscreen's background.
"No background" gives a white background.
"Use potential as background" gives a colored background showing the potential at any point.
"Use field strength as background" shows a colored background based on the strength of the electric field.
The menu labeled "Grid Lines" controls the grid of points and the way their information is displayed.
"No grid" makes the grid points disappear along with their grid lines.
"Uniform Length" makes all the grid lines the same length, showing direction rather than field strength.
"Normal Length" makes the length of the lines proportional to field strength, showing direction and field strength.
"Iron Filings" replaces grid lines with randomly scattered iron filings. Iron filings are scattered such that they are denser in regions of high field strength.
The check box labeled "Iron Filings" controls a set of iron filings. Checking or unchecking the box turns the filings on and off, respectively.
There are several options in the viewscreen.
Clicking and holding on any place in the screen that is not occupied by a charge displays information about the point you've clicked on: the X coordinate, Y coordinate, X field strength, Y field strength, and potential respectively.
Clicking and dragging a charge moves the charge.
Pressing the add charge button followed by clicking on the screen adds a charge.
Pressing the delete charge button followed by clicking on the screen deletes a charge.