Magnets

What is Faraday's law of electromagnetic induction in words?

The induced EMF is equal to the rate of change of flux linkage.

What is the equation form of Faraday's law?

𝜺 = −𝒅(𝑵𝝓) 𝒅𝒕

What quantity is changing to cause the EMF in an electromagnetic induction setup?

The magnetic flux (𝝓) is changing.

How does the setup cause the magnetic flux (𝝓) to change?

As the magnet drops through the coil.

What happens to the polarity of induced current as the magnet passes through the coil?

The EMF/current reverses in polarity as the magnet reaches the halfway point.

Why does the induced current reverse in polarity when the magnet moves?

Because a north pole enters then a north pole leaves the coil.

What explains the changes in the size of EMF during electromagnetic induction?

The size of EMF increases as the magnet moves faster (accelerates) while leaving, which increases the rate of change of flux linkage.

What happens when a bar magnet is dropped through a coil of wire connected to a resistor and data logger?

A current is induced in the coil.

How does the movement of the magnet affect the induced current's graph?

The shape of the graph reflects the rate of change of the magnetic flux as the magnet passes through the coil.

What is Lenz’s law and how is it related to electromagnetic induction?

Lenz's law states that the direction of induced current is such that it opposes the change causing it.