DC Circuits
RC Circuits
We will consider a Resistor and Capacitor connected in series with each other and with a switch.
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What is the voltage across the resistor (VR = VAB) or the voltage across the capacitor (VC = VBC) as a function of time, after the switch is closed?
How does charge on the capacitor q affect VC?How does VC affect the current I?
At time t = 0,
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As time continues, charge builds on the capacitor, the current decreases, and finally,
This is the "time constant" or "characteristic time" or "relaxation time" of the circuit.
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Or, we might begin with a charged capacitor and close the switch at t = 0. Then,
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