Final answer:
The poles in a three-phase alternator are set 120 degrees apart to provide three distinct phases of AC power. The use of multiple wire loops increases the maximum voltage, and Kirchhoff's junction rule can be confirmed by measuring currents at the points where branches meet or split.
Step-by-step explanation:
When discussing the operation of a three-phase alternator, the poles are spaced 120 degrees apart. This spacing provides three distinct phases of AC power, each phase shifted by 120 degrees from the others. This setup enables the production of a constant output as the alternator's rotor turns within the stator.
Additionally, to address part of the information provided, if an alternator's coil in a generator rotates within a magnetic field, changing the number of wire loops affects the maximum voltage output. By using three wire loops instead of one, the maximum voltage is effectively tripled due to the increase in the number of loops cutting through the magnetic field lines, which is a direct application of Faraday's law of induction.
Moreover, when measuring currents in a circuit to confirm Kirchhoff's junction rule, the most strategic points are those where different branches meet or split. This is because the rule maintains that the total current entering a junction must equal the total current leaving it.