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Niles
#1
Dec21-08, 04:43 AM
P: 1,863
1. The problem statement, all variables and given/known data
Hi all.

Please take a look at the attached circuit. I want to find the current through the capacitor, and of course I will use Kirchhoffs laws for AC-current.

In this case, ε(t) = ε_0*cos(ωt).

My question is: If this was an DC-circuit, I would define e.g. counterclockwise to be positive, and then go through the circuit. When I see an EMF which has the terminals the correct way (i.e. it wants to "send" the current through CCW), it gets a "+".

In this case with the AC-circuit, I don't know which way the EMF wants to send the current, because it changes. Should I always just give ε_0 "+"? Or does the direction in this case even matter?

Thanks in advance.

Regards,
Niles.
Attached Thumbnails
ac_circuit.PNG  
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