The appropriate product category
- When AC voltage E is applied to a load (e.g., a device), the phase of the AC current I flowing in it generally lags behind or leads the voltage E by amount θ. More specifically, when the load is purely resistive, there is no phase shift. When the load is inductive (i.e. a coil), it lags by θ. When the load is capacitive (i.e. a condenser), it leads by θ. The product of the current I and the voltage E times the cosine of the phase difference (cosθ) is the power P. Cosθ is the power actor.