Is the circuit right?

Question

^{simulate this circuit – Schematic created using CircuitLab}

I have found this questions and the circuit seems worong to me because the output terminal hasn't end point.

If we add a more diode into the circuit will it be explainable? is the circuit has been drawn in a right way??

Answer 1

It would work if the transformer had a center tap and the unused wire was connected there.

^{simulate this circuit – Schematic created using CircuitLab}

Now it is a full wave rectifier utilizing separate transformer windings wor each half wave. In the old days a transformer with a middle tap was cheaper than adding two extra diodes as used in a Graetz cell.