In a Y connected system, which of the following formulas relates power to voltage, current, and power factor?

In a Y connected system, the correct formula that relates power, voltage, current, and power factor is P = Ep IL Cos φ.

In this equation, P represents the real power consumed in the circuit, Ep is the phase voltage, IL is the line current, and Cos φ (where φ is the phase angle) is the power factor.

The reason this formula is appropriate is that it reflects how real power is calculated in a three-phase system. In a Y arrangement, the line voltage is related to the phase voltage, and the line current is the same as the phase current. Thus, when calculating power in a three-phase system, the formula effectively captures the relationship between the voltage present across the load, the current flowing through the load, and how effectively that power is being used (represented by the power factor).

Using the phase voltage (Ep) and the line current (IL) allows for an accurate calculation of real power while appropriately accounting for the nature of the Y connection and the power factor, which indicates how much of the apparent power is being turned into useful work. This makes it essential for understanding power relationships in electrical systems, particularly in power distribution and consumption scenarios in Y connected configurations.