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Example 5: An ac generator has 12 turns of<br />
wire of area 0.08 m 2 . The loop rotates in a<br />
magnetic field of 0.3 T at a frequency of 60<br />
Hz. Find the maximum induced emf.<br />
w = 2pf = 2p(60 Hz) = 377 rad/s<br />
Emf is maximum when q = 90 0 .<br />
E<br />
max<br />
=NBAw; Since sinq 1<br />
E =<br />
max<br />
2<br />
(12)(0.3 T)(.08 m )(377 rad/s)<br />
. n<br />
q B<br />
x<br />
f = 60 Hz<br />
The maximum emf generated is therefore:<br />
E max = 109 V<br />
If the resistance is known, then Ohm’s law (V = IR) can<br />
be applied to find the maximum induced current.
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