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Learning Introductory Physics with Activities

Section 11.11 Faraday’s Law

Definition 11.11.1. Faraday’s Law.

Faraday’s Law says that if the magnetic flux through a surface changes with time, a voltage is induced within the current carrying material:
\begin{equation*} V_{induced} = - \frac{d\mathit{\Phi}_B}{dt} \end{equation*}
Table 11.11.3. Example Magnetic Induction Table
\(\vec{A}\) Out \(xy\)
\(\vec{B}\) out \(B\)
\(\Phi_B\) \(+\) \(Bxy\)
\(\frac{d\Phi_B}{dt}\) \(-\) \(Bxv_y\)
\(V_{ind}\) \(+\) \(Bxv_y\)
\(I_{ind}\) \(ccw\) \(\frac{Bxv_y}{R}\)

Exercises Activities

The current-carrying wire below is being pulled downward, away from the square metal loop.
Figure 11.11.4. A long wire carrying current to the right below a wire loop.

1.

As the wire is moving, is there a clockwise current induced around the loop, a counterclockwise current, or no current? Create a magnetic induction table to explain your reasoning.

2.

Describe a different experiment you could do with the setup in the figure that would result in an induced current in the loop. What direction will the current in the loop be for your experiment, and why?