# PLC Activity #6 Magnetic Induction

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## PLC Activity #6

### Magnetic Induction

Due: see webpage for due date

How to get credit for this activity

First, sign-in at the computer and sign-out when the activity is complete. Show your work and results to a PLC tutor so they can check your work and initial the signoff sheet. Be prepared to answer questions about the activity or your results.

Question 1

The figure shows four different circular loops that are perpendicular to the page. The radius of loops

3 and 4 is twice that of loops 1 and 2. The magnetic field is the same for each. Rank in order the magnetic fluxes

1

through

4

, from the largest to the smallest. Some may be equal. Explain

Question 2

The magnetic flux passing through a coil of wire varies as shown in the graph. During which time interval(s) will an induced current be present in the coil? Explain.

Question 3

There is a counterclockwise induced current in the conducting loop. Is the magnetic field inside the loop increasing in strength, decreasing in strength, or steady?

Question 4

The power lines that run through your neighborhood carry alternating currents that reverse direction 120 times per second. As the current changes, so does the magnetic field around a line. Suppose you wanted to put a loop of wire up near the power line to extract power by "tapping" the magnetic field. Sketch a picture of how you would orient the coil of wire next to a power line to develop the maximum emf in the coil. (Note that this is dangerous and illegal, and not something you should try.)