What happens to the power factor when the lead or lag is large?

When the lead or lag is large, the power factor decreases, making it small. The power factor is a measure of how effectively electrical power is being converted into useful work output, with values ranging from 0 to 1. A large lagging or leading component (indicating a significant amount of reactive power) influences the overall efficiency of power usage.

When the power factor is close to zero, it signifies that a significant portion of the power is being utilized for reactive purposes (like creating magnetic fields in inductors or electric fields in capacitors) rather than for productive work. This condition typically results when the system's reactive power component is substantial relative to the real power—resulting in a lower power factor.

The other choices do not accurately describe this relationship. Keeping the power factor at unity requires that the reactive power is balanced with the real power, which does not happen with large lead or lag conditions. Similarly, power factor values above 1.00 are not mathematically possible, and the power factor does change significantly when there is a large lead or lag.