Which variable represents the line-to-line voltage in a WYE transformer?

In a WYE transformer configuration, the variable that represents the line-to-line voltage is typically denoted as EP. In three-phase systems, the line-to-line voltage is the voltage measured between any two of the three phases, while the line-to-neutral voltage (also referred to as the phase voltage) is the voltage measured from any phase to the neutral point.

In a WYE connection, the relationship between the line-to-line voltage and the line-to-neutral voltage is defined by the following equation:

Line-to-Line Voltage = √3 × Line-to-Neutral Voltage

Since EP represents the line-to-line voltage, it captures this fundamental concept of three-phase systems effectively. This understanding is crucial for calculations involving WYE configurations, where knowing the relationship between these voltages is essential for proper transformer operation and design.

The other variables such as EL, IL, and IP do not typically represent line-to-line voltage in the context of WYE transformers, which is why they are not correct choices in this scenario.