physics / Electricity & Magnetism / free

Magnetic Fields

Change current and motion to see field and force respond.

Follow the mechanism1 / 3

Charge is moving through a field. A magnetic field acts on moving charge, not on a stationary charge in this model.

current creates a magnetic fieldB ∝ I / r

Focus the idea

field strength2.50

distance2 m

charge force25.00

directionup

Current 5 ADistance 2 mMoving charge 2Charge speed 5 m/s

Doubling distance weakens this field model by the same inverse factor; current sets the field’s strength.

Magnetic fields act on moving charge. A stationary charge can sit in a magnetic field without feeling the magnetic force shown here.

04 / PRACTICE

Make the idea yours.

0 / 3 checked

Use the model, then answer without looking back. Each check isolates one decision a learner should be able to make after this lesson.

CHECK 1 / 3