# Find phase angle of RLC network

1. Feb 13, 2015

### D.B0004

1. The problem statement, all variables and given/known data
Please see attachment for circuit and parameters.

2. Relevant equations
i --> 90 phase angle for inductor so Z of inductor = 0.5<90
sum of voltages = 0
#<40 = #*cos(40) + i*sin(40)*#

3. The attempt at a solution
shteii01 - 100 + 0.5<90 + V2<theta = 0 --> 100 + 0.5*cos(90) + i*sin(90)0.5+V2*cos(theta)+i*sin(theta)*V2 = 0 --> two unknowns
OR
delta V = I * Z and then take V1 - delta V to find V2. The work seems simple but I get the wrong answer! Note that the answer I have in the attachment was my first solution which I did in my head - not the one I got from the methods shown above. Thanks for the help.

#### Attached Files:

• ###### Screen Shot 2015-02-12 at 6.49.54 PM.png
File size:
14.7 KB
Views:
81
2. Feb 13, 2015

### Staff: Mentor

I don't understand your first approach because you would appear to be adding voltages and impedances together in some way. But your second approach should work just fine. Since you are given the current you can find the potential drop across the inductor as you say. Can you show the details of that attempt?