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Licensed Philadelphia Electrician
Philadelphia License # 3516 - 16765
Obviously posted by a civilian ..
Obviously intended to be a 120/240 service as found in homes.
Since loads are identical, the open neutral would not impact the appearance of the lamps, as the same current would flow through both with an equal voltage drop across each of the now series-connected lamps.
A much more interesting question would be "what would be the resulting effect if there were FOUR, or TEN, 100 watt lamps on leg [obviously not phase] A and ONE 100 watt lamp on leg B?"
[Clue: this is why TVs burn up when you lose your neutral!] http://wilberelectrical.blogspot.com/
On a Single Phase 120/240 service, the 2 "legs" are commonly referred to as phase "A" and phase "B" as well as Leg "A" and Leg"B". Generally I hear the term "phase" more often, though it may be a misnomer. Lou
Robert's circuit is an interesting and wild one. That's why it's super important to have good electrical connections. When a neutral becomes disconnected some very wild and nasty things can sure happen. I have to get working on drawing up a few circuits and scan them. I'll post a few pictures and see how many of you have your thinking caps on. One of them will get everyone laughing once you figure it out.
I'm new to this forum so I thought I would also add to this...I've not gone through all the responses - just a few.
I'm not an electrician but I wonder why the Phase A and Phase B are named as such. Without knowing the phase relationship between A and B you cannot answer this question - so from that point of view E would be the answer since it says none of the above.
Assuming phase A and Phase B are 120V, 180 degree out of phase then I agree that cutting neutral will not affect the result - both bulbs will continue to burn since the return current will always choose the path of the lower potential which is the leg 180 out of phase.
I saw someone had posted that if one bulb burns out the other will not light. I cannot see that myself - if that happens the return current will travel via the neutral line and the other bulb should stay lit.