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A silver wire 2.6mm in diameter transfers a charge of 420 C in 80min . Silver contains 5.8*10^28 free electrons per cubic meter.

What is the current in the wire?

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I have correctly solved this problem using I= Q/t, but I am a bit confused by this. Correct me if I'm wrong, but this is the formula for *average* current. I thought that in general, I= dQ/dt, and that only in cases when you have a complete circuit is the current the same everywhere. In this special case, the average current would be equal to the instantaneous current, but we are not given that we have a complete circuit. So why do we use the formula for average current?

Thanks!

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# Homework Help: Current: Average vs. Instantaneous.

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