Which configuration allows for the same line and phase voltage?

The Delta configuration is the one that allows for the same line and phase voltage. In a Delta configuration, connections are made between the ends of the coils in a closed loop, which creates a triangular shape. This results in the phase voltage (the voltage across each coil) being equal to the line voltage (the voltage measured between any two lines in the electrical system).

In Delta, the phase voltage is directly equal to the line voltage because each phase is connected directly across the supply lines. This means that each load connected in the Delta configuration experiences the full line voltage.

In contrast, the Star configuration, which is sometimes considered, provides a different relationship where the line voltage is greater than the phase voltage. The phase voltage is obtained by dividing the line voltage by the square root of three.

Parallel and series configurations pertain to the arrangement of components such as resistors, capacitors, or inductors, rather than directly addressing the relationships between line and phase voltages in three-phase systems. Therefore, they do not apply to the question regarding maintaining the same line and phase voltage.