AP Physics C: Electricity and Magnetism Flashcards: Electromagnetic Induction
Written by AP Content Team, Verified for 2026 AP Exams, Last updated: May 2026
Review key ideas with interactive flashcards. This set includes 10 cards to help you master important concepts.
What does Maxwell's third equation, $\oint\vec{E}\cdot d\vec{l}=- rac{d\Phi_{B}}{dt}$, imply about the nature of the induced electric field?
This equation shows that a changing magnetic flux creates a non-conservative, circulating electric field, which is the source of the induced emf.
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What does Maxwell's third equation, $\oint\vec{E}\cdot d\vec{l}=- rac{d\Phi_{B}}{dt}$, imply about the nature of the induced electric field?
This equation shows that a changing magnetic flux creates a non-conservative, circulating electric field, which is the source of the induced emf.
What is Faraday's Law of Induction?
Faraday's law describes the relationship between a changing magnetic flux and the resulting induced electromotive force (emf) in a system.
What fundamental condition is required to induce an electric potential difference in a circuit?
An induced electric potential difference is created by a change in the magnetic flux passing through the area enclosed by the circuit.
How do Faraday's Law and Lenz's Law work together to describe induced emf?
Faraday's Law determines the magnitude of the induced emf, while Lenz's Law determines the direction of that emf.
If the magnetic flux through a stationary loop of wire is constant, what is the value of the induced emf?
If the magnetic flux is constant, its rate of change ($d\Phi_{B}/dt$) is zero, and therefore the induced emf is also zero.
State the mathematical expression for Faraday's Law of Induction.
The equation for the magnitude of the induced emf is $|\mathcal{E}| = | rac{d\Phi_{B}}{dt}|$.
According to the equation $|\mathcal{E}| = | rac{d\Phi_{B}}{dt}|$, what happens to the magnitude of the induced emf if the magnetic flux changes more rapidly?
If the rate of change of magnetic flux ($d\Phi_{B}/dt$) increases, the magnitude of the induced emf ($|\mathcal{E}|$) also increases, as they are directly proportional.
What is Maxwell's third equation?
Maxwell’s third equation is Faraday’s law of induction, which mathematically describes the relationship between a changing magnetic flux and an induced electric field.
What is the purpose of Lenz's Law?
Lenz’s law is used to determine the direction of an induced emf that results from a changing magnetic flux.
What is the key difference in what Faraday's Law ($|\mathcal{E}| = | rac{d\Phi_{B}}{dt}|$) and Maxwell's third equation ($\oint\vec{E}\cdot d\vec{l}=- rac{d\Phi_{B}}{dt}$) describe?
Faraday's law relates changing magnetic flux to the total induced emf in a loop, while Maxwell's equation provides a more fundamental description relating changing magnetic flux to the induced electric field at any point in space.