Complex Notation - Electrical Circuit

[amy1983]

Homework Statement

1 (a) using complex notation, find an expression for the output voltage, v0
1 (b) using complex notation, find an expression for the input current, ig, and hence determine the phase angle of ig relative to vg

Homework Equations

The Attempt at a Solution

See attached two attempts, in jpgs. I've gotten myself very confused! If someone could advise that would be great.

 

[gneill]

1.2 mH is not the same as 0.001 H; you've dropped a significant figure. This in turn has significantly altered your impedance value for the inductor, with the error propagating through your further calculations.

The input is specified as a voltage source, and you've treated it as a current. This is not correct.

You've then assumed that both the resistor and the inductor are conducting the entire "current" of 40A. They are in parallel so this is not possible; Parallel branches have the same potential difference, but not necessarily the same current. It's series components that have the same current.

 

[amy1983]

Thank you gneill, i'll have to look at it and perhaps get a physics tutor.