Current and Voltage in series and parallel circuits

[JESRR]

Voltage is constant in a parallel circuit and additive in a series circuit and amperage is additive in a parallel circuit and constant in a series circuit. Can anyone explain why this is?

 

[Basil]

current adds in paralell circuits: because current is charge per unit time so if you are inyecting charges to a given rate (current) by two diferent braches into the same sink you have to add. Do think in water: 1 Liter/seg in one hose plus 3 liter/sec in the other and you have 4 liters/sec.

current doesn't changes in series circuits: the only way the current would change in a series circuit is if charge disapears. Of couse charge doesn't disapear, charge is a kinf of matter and matter conserves.


potential in series circuits: each time you move trough a potential you make a work, work adds up.

potential in paralell circuits: if a difference of potencial would arise charges would move to equalize it. Do think in water communicating vessels

 

[djalli]

always think flows currents in a node are coming from let says three different wires. In every wire there is a suface and a flow of current in it. It adds up eventually.

I a single straight wire it is the same wire, same flow is always. Try to visualize it mentally.

 

[JESRR]

Very interesting way of explainging it. Thanks for the help.

 

[jzflyer]

Voltage is the potential between two different place.
so no matter how many path betweent that two point, the potential is same.

 

[starfish]

In series circuit , sum of voltage drops accross a loop should be zero.....
So if i have a battery of 5 volts and 2 resistors of equal value connected in series with it...........then the 2 resistors will have 2.5 volts each .......

5volts=2.5volts 1st resistor + 2.5 volts 2nd resistor..........

Thats why it sums up........

As far as current is concerned , think of a main pipeline branching into 4 pipelines ............. the sum of all the water flowing in the 4 pipelines will be equal to the main pipleline.........That's the same with the current in some circuit.......Currents entering a node should be equal to the current leaving from a node.

 

[delay]

Kirchoff's voltage and current laws is the background for these phenomena.

 

[golfbumb]

Expanding on "delay's" post.

Kirchoff's current law (KCL) states the sum of the currents entering a node must equal the sum of the currents leaving the node. This is an application of the principle of the conservation of charge.

Kirchoff's voltage law (KVL) says that the sum of the voltage rises (e.g., batteries) and drops (e.g., resistors) in any loop must equal zero. This is an application of Faraday's law.

Therefore, applying KVL the total voltages in a series circuit are additive while applying KCL the current is constant in any series loop.

Conversely, applying KCL the total current through (leaving) a parallel circuit is the sum of the individual currents and by applying KVL the voltage in a parallel set of components is equal (they form loops with each other -- and, instinctively, they are across the same point).

 

[Kevin Weddle]

You have to look at the resistance for your answer. The answer lies in how the resistance adds in series and is divided in parallel. The way to look at it is in terms of a square piece of carbon. If you add length to the carbon it produces more resistance. The wider you make the carbon the lower the resistance. If you notice that two resistors of the same value produce half. Three produce one third. Four produce one fourth. This is about fractions. It is about dimensions.