Three-phase power is transmitted in phases that are _______ degrees apart.

Three-phase power is transmitted in phases that are 120 degrees apart. This phase arrangement is fundamental in three-phase systems as it provides a balanced load and continuous power delivery. When the phases are spaced evenly at 120 degrees, it allows for the generation of a constant and smooth power output, which is critical for the operation of motors and other electrical equipment that rely on three-phase power.

Each phase reaches its peak voltage at 120-degree intervals. This means that at any given time, one of the three phases is at its peak, while the other two are at different points in their cycles. Consequently, this arrangement optimizes the efficiency of electrical systems by ensuring that power is consistently available, reducing the likelihood of voltage dips that can occur with systems that operate on different phase angles.

In examining the possible alternatives, 90 degrees would create an asymmetrical phase distribution, while 180 degrees would simplify the system to just two phases, leading to imbalanced power and the inability to realize the advantages of three-phase power. A spacing of 240 degrees does not correspond to standard phase configurations in a three-phase system either. Thus, 120 degrees is the correct configuration for effective three-phase power transmission.