I am really confused with the above problem.
I get the logic of the solution
Since,the line voltage ratio is 2. So, current will be half. Thus 50.
But I am confused should we take +30 or -30.
Shouldn't it depend on the connection whether it is Yd1 or Yd11.
Please help me in understanding this concept.
-- EDIT --
I was trying to draw some phasors which I have attached below
Assuming IA winding and Iab winding are in phase
In this case taking Ib = 100 <0 gives me IA = 50 <30
Please help me with current phasors, I am really confused.