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Unformatted text preview: t is the rate (in Joules/s = Watts) at which magnetic energy stored
in the inductor, L, is decreasing? 12 V L 2 mH 60 Ω 20 Ω
1. calculate current in
before the switch is
opened. 29 W
15 W This is the current that must
go through the two resistors
when the switch is opened.
Use it to calculate power. Version 1 Page 9 The rate that energy in
the inductor decreases is
equal to the power
dissipated in the two
resistors because that is
where the energy is
going. 16. Current I is charging a circular parallel plate capacitor with plate radius of R. The
circulation of the magnetic field, B dl , around a coaxial circular path between the
plates with r = R/3 has some definite value. Consider two surfaces bounded by this
circular path; the round flat surface (shaded); and the open soup-can (dashed). What can
we conclude from the Ampere-Maxwell Law?
The total current of all kinds flowing in to the cylinder must be
exactly equal to the total current of all kinds flowing out. (this is a
paraphrase of the Kirchhoff junction rule). I The cylinder only covers 1/9 of the area of the capacitor plate. This
means only 1/9 of the displacement current of the capacitor goes
through the shaded side. To make up the difference 8/9 of current
must go out the sides in the form of conduction current (remember,
the charge has to spread out across the entire plate...). A) The "current" (conduction + displ...
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This document was uploaded on 03/11/2014 for the course PHYSICS 240 at University of Michigan.
- Fall '08