Wye-Delta transformation

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1. Jan 13, 2015

arpon

To prove the wye-delta transformation formula, it is said 'If the two circuits are to be equivalent,
the total resistance between any two terminals must be the same.' But why ? I can't convince myself that it is sufficient condition for the equivalence of circuits.

2. Jan 13, 2015

zoki85

In order to input/output currents for given voltage be the same. What else did you expect to mean by the equivalence of the circuits?