The issue is the definition of the two currents. The diagram explicitly defines the inductor current to be downward through the inductor. The diagram does not define the direction of the capacitor current directly, but rather does so indirectly via the passive sign convention. The diagram defines the voltage polarity across the capacitor and the passive sign convention states that the current through a device enters the positive terminal of the defined voltage across the device. Thus the direction of the capacitor current is also downward through the capacitor. Hence the inductor current and the capacitor current will always be equal and opposite once the switch opens.From the picture right down below, I don't understand. why the Ic current be negative?
if it's a series circuit I think it should has the same value and same direction for currents.
for this example, Find the Vc(t) and IL(t) for t>0 (after the switch is opened).
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