In a dual-voltage motor, how is the potential difference across one phase in a Y-connected winding related to the line voltage?

In a Y-connected (also known as star-connected) winding, the relationship between phase voltage and line voltage is derived from how the voltages are configured in the connection. In a three-phase system, the line voltage is the voltage measured between any two lines, whereas the phase voltage is the voltage measured across a single phase in the winding.

For a Y-connected system, the relationship can be defined mathematically as follows:

Phase Voltage = Line Voltage / √3

This means that for each phase, the potential difference (or phase voltage) is equal to the line voltage divided by the square root of 3. This ratio comes from the geometric arrangement of the phases in a three-phase system, where the phases are 120 degrees apart; therefore, the vector sum of the voltages results in this relationship.

Thus, the potential difference across one phase in a Y-connected winding is indeed divided by the square root of 3 when compared to the line voltage, confirming that the answer is correct.