# Homework Help: Find alternators magnetic field?

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1. Apr 12, 2017

### jlmccart03

1. The problem statement, all variables and given/known data
You're an electrical engineer designing an alternator (the generator that charges a car's battery). Mechanical engineers specify a 10-cm-diameter rotating coil, and you determine that you can fit 250 turns in this coil. To charge a 12-Vbattery, you need a peak output of 16 V when the alternator is rotating at 1300 rpm.

What do you specify for the alternator's magnetic field? HINT: Notice that the rotation rate of the coil is given in revs per minutes, not revs per second.

2. Relevant equations
I think Guass Law for B fields?

3. The attempt at a solution
I really do not know where to start. I am in general confused on what form of equation I should be using. I want to say using gauss's Law for B fields, but I can't come up with a definitive solution. Any guidance would be appreciated.

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2. Apr 12, 2017

### CWatters

Have you googled.. voltage produced by a rotating coil?