I'm working with a parallel circuit with resistors and inductors. When t =0, a circuit is closed. there is initially no current running though the inductor which means that all of the current is running in series. I also have two resistors in this series which means that I can find the source current via ohm's law. What I'm confused about is whether or not this source current changes any after current starts flowing through the inductor

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naveenbabbar · Answer

Question is not clear. Show diagram

anonymous · Answer

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Three resistors (R1 = 120 Ohms, R2 = 330 Ohms, and R3 = 240 Ohms) and an ideal inductor (L = 1.6 mH) are connected to a battery (V = 9 V) through a switch as shown in the figure below.

The switch has been open for a long time before it is closed at t = 0. At what time t0, does the current through the inductor (I3) reach a value that is 63% of its maximum value?

kropot72 · Answer

First we need to find the Thevenin resistance r, which is the resistance seen at the inductor terminals with the inductor removed and the battery replaced by a short circuit.$$r=\frac{120\times330}{450}+240=328\ \Omega$$
The time taken for the current to reach 63% of its maximum value is known as the time-constant and has the value L/R.
In this case the required time is given by:
$$\frac{L}{r}=\frac{1.6\times10^{-3}}{328}=you\ can\ calculate$$