I have to disagree with you JW...if you have 3 bulbs in parallel, and you lose one bulb, the voltage doesn't change.....all that changes is the current in the feed circuit, it drops....

the current does drop in the feed thats why the voltage goes up, every feed wire is rated for a certain power, and is like a resistor it drops some voltage, its going to drop more voltage with more load and less with less load. and i think that is far enough off the op'* original question. \thread for me

I disagree if it'* a parallel circuit.......If you have a 12 volt battery, hooked up to 3 bulbs in parallel, disconnecting/removing one or two bulbs will not change the voltage across the third bulb...

Gus is correct. No voltage drop in a parallel circuit. Just series.

Nice reading material...
https://www.swtc.edu/ag_power/electr...l_circuits.htm

what you guys are referring to is theory and that only is applicable to books. in the real world you have feed wires that are designed for cost. so you dont just have a simple battery and infinite amount of capability, the power has to go through whatever wire the designer for what ever device you are working on decided to spec and it is the smallest they can get away with. so its going to drop some voltage. wires drop more voltage when warm and the more current the warmer it gets so when you lose a bulb say you loose that current the temp goes down and the voltage to the load goes up.

i dont normally try to get into a credential listing but i went to school for and make my money at knowing electrical/electronics and have for many decades, we will put it that way

All I can say is......."Ouch!"

well all i can say is ive been there, you get into these classes and the books and stuff were written by engineers with no experience working on what they are teaching, so alot of times you get to your job and alot of stuff doesn't apply. to me real experience is worth way more than much book learning

Am I missing something, or was that info on parallel circuits not based on Ohm'* law?
All I see mentioned there is a Law, and formulas mentioned, what written there is theory?
Not asking to be argumentative, so please do not take it that way, in school I only took pre-vocation, and vocation, so that is the extent of my knowledge, I just thought Laws and Formulas were more than just theory?

I may just test this out myself, all I need is a 12v battery, and 3 light bulbs wired in parallel, I am no electronics engineer, but I have a multimeter, and I know enough to be able to test this out, I'll try to get some 12v bulbs when I get the money, will probably be next month though, as I do not have any extra funds at the moment.

if you do it as you suggested it will work as the books say, because the power has no other factors to affect it. so the voltage at the load will be exactly what it is at the supply. and parallel bulbs wired this way will not know any difference if there is one or 50. but the problem is that normal devices are not 6 inches from the battery, so you have to factor in the wire basically as resistors that vary with heat related current.