How does voltage get divided to components in a circuit?

[Calum_]

Ok, so if you have a 9v battery and connect 2 bulbs to it (in series) each bulb recieves/uses 4.5v right?
And if you have 3 bulbs then 3v per bulb etc.
But how does the bulb "know" to only use 3v? You would think the first bulb would use 9v and then there's none left for the other 2.
Can anyone explain this?
Thanks.

 

[grimfox]

It's Ohms law. E(voltage) = I(current,amps) * Resistance(ohms) Each light bulb has equal resistance therefore the voltage splits evenly as you attach more of the same bulbs in series. But as you add more resistance in series the current through the total circuit is reduced proportionally to the resistance. As the current is reduced the voltage measured across each bulb is also reduced because the values are tied together by the formula above. It's a pretty big topic. If you google ohms law there are lots of explanations that are probably better than mine.

 

[Eximo]

If you hit up youtube you can find complete lectures on the subject.

 

[Eximo]

Also look up Voltage Drop, as that is the answer to your exact question.

 

[k1114]

Electricity needs a complete circuit to flow so it's going through all components. This is where your theory completely falls apart when you assume the first takes all the power. Electricity won't stop, it keeps flowing until there is no power or resistance is high enough to stop power. The battery is both where the power is from and where it is being attractive back to. The light bulbs in the circuit are just along the path of where it is traveling. So all lights have power and it gets divided up.