# Inductance problem

1. Dec 4, 2013

### dwn

1. The problem statement, all variables and given/known data

An inductor has an inductance of 0.45 H and internal resistance of 2.5 . If the H
inductor is connected to a 120-V (rms) source at 60 Hz, what is the current (rms) through
it?

2. Relevant equations

XL=2pi*f*L
V=IR

3. The attempt at a solution

I don't have any idea and my brain is wrecked! I'm having a difficult time finding this bridge.

2. Dec 4, 2013

### xophergrunge

You don't want to use V=IR, that doesn't take into account the reactance of your inductor. For a simple LR circuit V=IZ.

3. Dec 4, 2013

### dwn

Even using Z, I still arrive at 48 A. 120/2.5 = 48 A Which is not the correct answer. It is .7 A.

Last edited: Dec 4, 2013
4. Dec 4, 2013

### xophergrunge

I get I = 0.707 A.

5. Dec 4, 2013

Z≠2.5Ω.

6. Dec 5, 2013

### Staff: Mentor

How do you determine the impedance of a series circuit of 0.45 H in series with a resistance of 2.5Ω ? You have studied complex number arithmetic?