# 2nd Order Circuits...quick question

Discussion in 'Homework Help' started by TheRealVasile, Aug 22, 2013.

1. ### TheRealVasile Thread Starter New Member

Aug 1, 2013
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is the 2 circled in red due to the initial condition of 2A?

2. ### t_n_k AAC Fanatic!

Mar 6, 2009
5,448
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Yes - presumably the initial inductor current.

Mind you, the question itself lacks clarity in that regard, as nowhere on the schematic is the current I(t) actually annotated.

3. ### WBahn Moderator

Mar 31, 2012
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My guess (and I agree that the problem should have been more explicit) is that the I(0) is the current for the entire circuit, not just the inductor. This is based on it not being subscripted at all, just like the V(0) isn't. Quantities with matching subscripts (including no subscript) are generally matched quantities. As for the direction, the best you can do is to assume the passive sign convention, which has this being the current going from the + terminal of the V(t) indication through the circuit and back out the - terminal.

Under these assumptions (which, while I think they are the best ones to make and most likely the correct one, is still a sad commentary on the person writing the question), what is the initial inductor current?

There is actually one other assumption that must be made and the validity of this one is really suspect -- which could be used as an argument for claiming that the I(0) given really IS specifically the inductor current. But, again, what direction should be assumed for it?