Circuit analysis -- Find the complex apparent power of I(g2)

[gruba]

Homework Statement

Given the circuit of sinusoidal current (attachment 1) with given data:
$\underline{Z_3}=200(3-j4)\Omega, \underline{Z_4}=100(3+j20)\Omega, \underline{Z_5}=100(3+j4)\Omega, \underline{Z}=100(2+j5)\Omega, \underline{I_{g2}}=-10(2-j)mA$
After the switch is closed, the increment of voltage 1-2 is given: $\Delta U_{12}=(4+j3)V.$
Find the complex apparent power of $\underline{I_{g2}}$ after the switch is closed.

2. The attempt at a solution
By using superposition theorem, we can separate the given circuit into two circuits (attachment 2 and 3):

From the second circuit (attachment 2), we can find the voltage $\underline{U_{34}'}$.

In the next circuit (attachment 3) $\underline{I_{g1}},\underline{Z_1},\underline{Z_2},\underline{E_2},\underline{E_6}$ are not given.
Question: How to find the voltage $U_{34}=U_{34}''$ in this case?

Total complex apparent power is given by $\underline{S_{I_{g2}}}=\underline{{I_{g2}}^{*}}(\underline{U_{34}'}+\underline{U_{34}''}).$

 

[The Electrician]

This is a homework forum and the forum rules require you to show your attempt to solve the problem.

Are you required to use superposition to solve the problem?