Problem 81-1    Source:  Problem elaborated by the author of the site.

Be the voltage V_AN = 127 ∠60°. Find the corresponding line voltage.

Solution of the Problem 81-1

To find the line voltage, we must multiply the phase voltage by root of three (eq. 81-01) and the angle must be advanced by 30°. Recall that there is a correspondence between the voltages, when the first index is the same, in both line voltage and phase voltage. Like this:

Note that both V_AB and V_AN, have as their first index the letter A. Performing the calculation: