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**31.
ssm Two 0.68-m-long conducting rods
are rotating at the same speed in opposite directions, and both are
perpendicular to a 4.7-T magnetic field. As the drawing shows, the ends of
these rods come to within 1.0 mm of each other as they rotate. Moreover, the fixed ends about which the rods are rotating are connected by
a wire, so these ends are at the same electric potential. If a
potential difference of
4.5 x 103
V is required to cause a 1.0-mm
spark in air, what is the angular speed (in rad/s) of the rods when a spark
jumps across the gap? |
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The effective area the bar
creates for magnetic flux is pL2 for each
revolution or period |
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We drop minus sign again it is
related to polarity and N is 1 here.
Period relates to angular speed as |
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Since the rods swing in
opposite directions their free ends are going to be at oppositely signed
polarities |
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Solve for ω |
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