Mutual Inductance Problem

1. Mar 16, 2012

p75213

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

2. Relevant equations

3. The attempt at a solution
(5+j8)I1-j6I2-j3I2-j3I1*2=magnitude(12) degrees (60)
(5+j2)I1-j9I2=magnitude(12) degrees (60)

j2I2-j6I1-j3I1=0
-j9I1+j2I2=0

I put these equations into mathematics software and get the answers:
I1=magnitude (0.3091) angle (142.60) degrees
I2=magnitude (1.3909) angle (142.60) degrees.

These are not the answers provided. Can somebody show me where the error is?
1. The problem statement, all variables and given/known data

2. Relevant equations

3. The attempt at a solution

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2. Mar 16, 2012

Staff: Mentor

Can you show how you derived your equation? I'm concerned about how you treated the mutual inductance. Perhaps assign variable names to the component values for easy tracking in the equations.

3. Mar 16, 2012

The Electrician

You have a sign error. The equations should be:

(5+j8)I1-j6I2+j3I2-j3I1*2=magnitude(12) degrees (60)
(5+j2)I1-j3I2=magnitude(12) degrees (60)

j2I2-j6I1+j3I1=0
-j3I1+j2I2=0

4. Mar 16, 2012

p75213

Thanks for that. I had to go over some of the previous examples in the book. However I figured out what I was doing incorrectly.