What quantity did you change?
Labs / Physics
Electric Field
Scatter positive and negative charges across the canvas and the arrows reveal the electric field they build together — pointing away from plus, toward minus. Drag the ringed test charge anywhere to read the net force it feels, or click a charge to remove it.
Labs / Physics / Electric Field
Electric Field
Scatter positive and negative charges across the canvas and the arrows reveal the electric field they build together — pointing away from plus, toward minus. Drag the ringed test charge anywhere to read the net force it feels, or click a charge to remove it.
Why it matters
Why explore this?
Physics explains how changes in forces, energy, motion, and matter produce results we can measure. This model lets you test one part of that relationship at a time.
Explore
Try the model
charges 2|E| at test 0 N/C
Investigate
Questions to test
Predict first, try it in the model, then use what you observe to answer.
What to try
- With one positive and one negative charge, where do the arrows crowd together — and what does that crowding tell you about the field's strength?
- Switch to two like charges. Is there a spot between them where the test charge feels no force at all? Can you find it?
- Drag the test charge far from every charge. Why does the force arrow shrink so quickly — does the field fade with distance or with distance squared?
- Pile several positive charges into one corner. Does adding more charge make the field simply add up, or something more surprising?
- Load the quadrupole. How is its field different far away compared with a single charge or a simple dipole?
Explain
Make sense of what happened
Name the quantity you changed, the quantity that responded, and the physical rule connecting them. Use a readout or visible change as evidence.
Check
Before you leave
What measurable result changed?
Which physical idea connects them?
If you can answer all three using evidence from the model, you understand the main idea. If not, return to Explore and change one setting at a time.