PHYS 142 Lecture Notes - Lecture 12: Capacitance
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Phys 142: electromagnetism and optics - lecture 12: capacitance and capacitors part 2. Consider two capacitors c1 and c2 connected in parallel. The total charge drawn from the battery is q = q1 + q2. If capacitors c1, c2, c3, are in parallel, their equivalent capacitance is: If capacitors c1, c2, c3, are in series, their equivalent capacitance is: In series, the inverse capacitance, or elastance, is additive. The figure shows a capacitor being charged. As a small charge dq is lifted to a higher potential, the potential energy of the capacitor increases by: The total energy transferred from the battery to the capacitor is: Capacitors are important elements in electric circuits because of their ability to store energy. In terms of the capacitor"s potential difference, the potential energy stored in a capacitor is: