Electricity · Physics

Electric Field of a Charged Ring Simulation

See the electric field lines of a uniformly charged ring in 3D and move a test charge along its axis. Then watch a negative charge oscillate through the ring.

Interactive virtual lab · no download · works on phones and laptops

Chapter: Electric Charges and Fields
For: Class 12 · JEE
Time: ~12 min

Electric Field of a Charged Ring is a Pro simulation

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How to use it

1Drag to turn the 3D view.
2Move the test charge along the axis.
3Show the pulls of two opposite bits of the ring.
4Oscillation tab: release a charge from small and large distances.

What to notice

On the axis E = kQx/(x² + R²)^{3/2}: zero at the centre.
The axial field is largest at x = R/√2.
Far away the ring looks like a point charge.
A negative charge near the centre oscillates with ω = √(kQq/mR³).

For teachers

A ready-made teaching kit comes with this lab

Lesson plan
19 min, 4 steps
Ask the class
3 questions with answers
Quick quiz
5 questions, printable
Key formulas
3 formulas

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About the Electric Field of a Charged Ring simulation

A ring of uniform charge produces a field that is zero at its centre, because every bit of the ring is balanced by the bit opposite. Along the axis the sideways pulls cancel and the axial ones add, giving E = kQx/(x² + R²)^{3/2}, which peaks at x = R/√2 and falls off like a point charge's far away.

This charged ring simulation draws the field lines in 3D (traced from the ring's exact field and spun round the axis), moves a test charge along the axis, and plots E against x. Its second tab releases a negative charge on the axis: near the centre it oscillates in simple harmonic motion, and further out the swing slows down.

Also covers: field on axis of ring, ring of charge, maximum field r/root2, charge oscillating on axis of ring, electric field lines 3d.