Electromagnetic Induction: common misconceptions

If your child says… “The field along the paper counts too.”

Ask together

In the edge-on panel, do the field arrows cross the surface or run along it?

What’s true

A field running entirely along a flat surface contributes no flux through it.

If your child says… “A stronger steady field gives more voltage.”

Ask together

Once the magnet stops, what is changing through the fixed coil?

What’s true

Unchanging flux produces no induced voltage, however large the flux.

If your child says… “The induced field always opposes the existing field.”

Ask together

Would an outward induced field preserve the weakening inward flux or reduce it further?

What’s true

The induced field reinforces a weakening external field to resist its decrease.

If your child says… “Open ends mean there cannot be any voltage.”

Ask together

Must these separated charges circulate for the ends to have different voltages?

What’s true

Separated charges can produce voltage even when there is no complete conducting path.

If your child says… “Taking longer means less total flux change reaches the other coil.”

Ask together

With unchanged coils, would taking longer change the final field if the final current stayed unchanged?

What’s true

With fixed mutual inductance, current change sets the total flux linkage change in the secondary.

If your child says… “The coil always pushes against the current.”

Ask together

To resist a decrease, must the coil support the current or reduce it further?

What’s true

Induced voltage supports falling current, opposes rising current, and disappears when current stays steady.

If your child says… “Reversing current makes stored energy negative.”

Ask together

Does squaring a negative current give a negative energy?

What’s true

Reversing current without changing its magnitude leaves the final stored energy unchanged.

If your child says… “The most flux means the most voltage.”

Ask together

At a flux peak, is the flux curve steep or briefly level?

What’s true

Generator voltage follows the rate of flux change, rather than the amount of flux.