When voltage changes occur in rapid succession, with magnitudes large enough to cause lighting level variations. The human eye-brain response is most sensitive to periodic r.m.s. voltage changes that occur at around 8 - 10 cycles per second.
The capacity factor is the ratio of an actual electrical energy output over a given period of time to the maximum possible electrical energy output over that period. Nuclear power plants are at the high end of the range of capacity factors
EXAMIANS