Electromagnetic induction

Definition

Electromagnetic induction is the process by which a changing magnetic field within a closed loop of wire induces an electromotive force (emf) in the wire. It is a fundamental principle underlying many electrical technologies, such as transformers and electric generators.

5 Must Know Facts For Your Next Test

1. Faraday's Law states that the induced emf in a circuit is equal to the negative rate of change of magnetic flux through the circuit: $\mathcal{E} = -\frac{d\Phi_B}{dt}$.
2. Lenz's Law explains that the direction of the induced current opposes the change in magnetic flux that produced it.
3. The unit for measuring emf is the volt (V).
4. Mutual inductance occurs when a change in current in one coil induces an emf in another nearby coil.
5. Self-inductance involves a single coil where a changing current induces an emf within itself.

Review Questions

• What does Faraday's Law state about electromagnetic induction?
• $\text{How does Lenz’s Law affect the direction of induced current?}$
• $What is mutual inductance and how does it differ from self-inductance?$

Related terms

Magnetic Flux: A measure of the amount of magnetism, considering both the strength and extent of a magnetic field, typically measured in webers (Wb).

Electromotive Force (emf): The potential difference produced by electromagnetic induction or other sources that can drive an electric current.

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