Final answer:
The power factor of a DC system is 1.0, as voltage and current are in phase, meaning there is no loss of power due to phase differences; therefore, the DC system effectively utilizes all the delivered power.
Step-by-step explanation:
The power factor (PF) is an important concept in alternating current (AC) electrical systems, representing the amount by which the power delivered in the circuit is less than the theoretical maximum due to voltage and current waves being out of phase. When considering a direct current (DC) system, voltage and current are not out of phase; they are in alignment as DC provides constant voltage and constant current. Thus, the power factor in a DC system is essentially 1.0, as there is no phase difference to consider, implying that all the power is effectively used.
For a DC system, this means that the power delivered in the circuit equals the theoretical maximum, with no reductions due to voltage and current phase differences. Therefore, the correct answer to what the power factor of a DC system is, is option b.1.0.