Everything will flow backwards
What do you mean by a 'parallel delta' circuit -is there such a connection.
the hot and neutral are wired forwards the ground and neutral are wired backwards
A series circuit/
In a parallel circuit, the other bulb still works when one fails.
They are wired in series.
A parallel circuit
If it is a properly wired circuit (according to code) in the home, the breaker for that circuit will trip deenergizing the shorted circuit. If it is not properly wired, it could get hot and start a fire and possibly burn down the home.
the paralel
I you wired a light bulb in to the same circuit you have the possibility of over loading the circuit but other than that it would just be brighter.
There are many types of electrical circuits and each one is wired differently. Without knowing the specific circuit that needs to be wired, this question can not be answered.
An Amp Meter
if a light bulb is wired it lights if a motor is wired it turns