You´re the best, thanks a lot!
I solved it.
:thumbsup:
View attachment 17120
Congratulations, KA!
Now that you have solved it, I will let you in on a small trick that comes with experience in problem solving:
To solve the problem with the switch closed, start with the assumption that the two wye points are in fact connected.
Then look at the resulting current in the wire that connects the two wye points.
If that current is zero, then it does not matter whether they are actually connected or not.
That in turn tells you that since the wye point of the load is at the same voltage as the wye point of the source, the load voltages are just identical to the corresponding source voltages. But that is not actually the problem that was posed.
The original problem does not ask you what the voltage across the load Z is when the switch is closed, it asks you what the voltage across the switch is when it is open. That changes the whole analysis, and makes your solution, the appropriate one.
With the switch open, U
T will equal zero since I
T equals zero.
