Unformatted text preview: voltage across R is also going to zero. In other words, the current and voltage in different parts of the circuit is not “in sync.” Another word for this is “out of phase.” For a capacitor, the mathematical relationships are more complicated
because of the out
of
phase behavior of V and I: V (t ) = Vmax sin ! t I (t ) = I max cos ! t Power is calculated as before: P(t ) = Vmax I max sin ! t cos ! t Note that the average voltage and the average current are both zero as for the pure resistor circuit; however, the average power also happens to be zero. The average power in a capacitor is zero because while it stores up energy during charging, it then releases it during discharging. There are similar relationships for circuits that include inductors. Impedance It is difficult to express some form of Ohm’s Law as a function of time in terms of voltages and...
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 Spring '14
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