A useful measurement of current, voltage, resistance of AC power is ?

The useful measurement for current, voltage, and resistance of AC power is the power factor. Power factor is a measurement of how effectively electrical power is being converted into useful work output. It is calculated by dividing the real power (in watts) by the apparent power (in volt-amperes). A power factor of 1 indicates that all the power is being used effectively, while a power factor less than 1 indicates that some power is being wasted. Monitoring and improving power factor can help increase the efficiency and reduce energy costs in AC power systems.