physics / Fields & Forces / free

Maxwell's Equations

See electric and magnetic fields as one changing, connected system.

Follow the mechanism1 / 3

Charges and currents are sources. Gauss's law ties electric flux to enclosed charge, while magnetic flux through a closed surface always totals zero.

four laws, one field system∮E·dl = −dΦB/dt
Choose the law
⊙⊙⊙⊙⊙⊙⊙⊙⊙B out of page, increasing → E clockwisechanging B curls E

The four equations are compact source-and-response rules: charges and currents shape fields, while changing fields can themselves become sources. Together they predict electromagnetic waves. Values here are in relative units.

selected lawFaraday
dΦB/dt1.2 u/s
EMF ∮E·dl-1.2 u

A changing magnetic flux creates a circulating electric field (clockwise here). The minus sign is Lenz's law: the induced circulation opposes the change. That is induction as a field relationship, not a wire-only rule.

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

What does Gauss's law for electricity connect?