Constant Current in a series circuit

[Celluhh]

I think you had everyone shuffle with their seat!

People move to the vacant chair, leaving their previous seat behind.

Perhaps I should say "I saw an empty space move anticlockwise around the ring" The chairs themselves do not move, just the people - and the empty space.

um, i had the people move and the empty space as well but both went clockwise!=(

 

[Celluhh]

Providing there is zero resistance in the remainder of the circuit, yes. But in practice, some of the energy is lost in the resistance of other wires, the switch contacts, bulb's pressure contacts, etc.

energy can be lost?? hmmm what is there is resistance in the remainder of the circuit?

 

[NascentOxygen]

energy can be lost?? hmmm what is there is resistance in the remainder of the circuit?

There is resistance in every conductor in your circuit, so you lose some potential even before current reaches the bulb.

 

[Celluhh]

no as in, how do the charges ensure that they have enough electrical energy for the other resistances in the circuit as well?

 

[NascentOxygen]

no as in, how do the charges ensure that they have enough electrical energy for the other resistances in the circuit as well?

The battery voltage sets how much energy an electron will be given. Whatever energy the electrons have is then shared out, proportionally, between the various resistances around the circuit, according to the resistance they encounter. Current obeys Ohms law, even when the current comprises just a single electron going for an afternoon stroll.

 

[Celluhh]

ah so in a way the battery sees the resistance in the circuit then decides how much energy to give to each resistance??( for a series circuit) why did u suddenly talk about current?

 

[NascentOxygen]

ah so in a way the battery sees the resistance in the circuit then decides how much energy to give to each resistance??

Not really. The battery always gives each moving electron the same energy, this is set by the battery's voltage. The resistance determines how many electrons with that energy can flow. If not many are allowed to flow, then it must be a high resistance, so it won't get very warm. If resistance is low, then many electrons with that energy can go around the circuit, delivering a lot of energy to the resistance/s, which then get hot.

( for a series circuit) why did u suddenly talk about current?

I prefer to talk about current, because most electronics equations involve current.

 

[Celluhh]

Current obeys Ohms law, even when the current comprises just a single electron going for an afternoon stroll.

this sentence seems similar to what petero's analogy, but i don't really see how his energy depicts electrons and current flow in a circuit, and this sentence of yours seems similar to his analogy. would you mind elaborating it further in simple terms?

 

[Celluhh]

The resistance determines how many electrons with that energy can flow. .

ah, so the resistor resists the electron flow and the electrons which manage to get to the resistor will transfer its energy to the resistor. um wait, then what about current flow??

 

[NascentOxygen]

this sentence seems similar to what petero's analogy, but i don't really see how his energy depicts electrons and current flow in a circuit, and this sentence of yours seems similar to his analogy. would you mind elaborating it further in simple terms?

The actual charge carrier and related direction is almost always unimportant. So a stream of negative charge carriers moving from right to left is equivalent to a stream of positive charge carriers moving from left to right. They each transfer energy.

It remains a real shame that early scientists guessed that electricity in wires comprises positive charges moving from + to - , while we now know it's really negative charges moving from - to +. But as I said, either model works just as well, and the equations have by now been constructed around current.

 

[Celluhh]

yeah i know, but my teacher keeps emphasising on how current flows from positive terminal, electrons flow from negative terminal, as if it will affect our performance in the science paper.=(

 

[PeterO]

um, i had the people move and the empty space as well but both went clockwise!=(

I can only suggest you get hold of 6 friends, seven chairs and watch.

 

[NascentOxygen]

yeah i know, but my teacher keeps emphasising on how current flows from positive terminal, electrons flow from negative terminal, as if it will affect our performance in the science paper.=(

Well I think you should find that question a breeze.

 

[Celluhh]

ok so , electron flow and current flow is basically one and the same?i know its not really the same just cos scientists thought charges flow from positive terminal that's why we have the conventional current flow. but actually there's only one real flow- that's the flow of electrons from negative to positive terminal, but when we analyse circuits, if need be, we use the current flow. right? i think maybe that's why my teachers kept repeating it.