Question 11/97
A variable capacitor is connected to two terminals of a battery
of electromotive force E. The capacitor initially has a capacitance
C(0) and charge q(0). The capacitance is caused to change
with time so that current I is constant. Calculate the power supplied
by the battery, and compare it with the time rate-of-change of the energy
of the capacitor. Account for any difference.
This was a Candidacy Exam question at the University of Chicago.
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