Resistors and current

[umdnjmed]

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Why doesn't the value for current decrease after going through a resistor?
Based on the definition of current, "the amount of charge passing a given point per unit time," as the electrons are slowed down by the resistor and more time is required for them to go through, shouldn't the value for I decrease? In other words, I would think the rate at which charge flows (current) would be decreased by a resistor.

 

[Arctangent]

As far as the actual question, I usually relate a circuit to a river for conceptual questions. If a given river initially has uniform flow, consider that you build a dam at one point in the river (like a resistor). What actually happens to the water flow rate is not that all points besides the dam have the same speed, whereas the dam's flow rate decreases, but that throughout the whole river, the entire flow rate must decrease. This phenomenon actually has been noted in dams historically; construction of dams often leads to regions of fairly still water, and when dams have broken, the increase in water speed occurs dramatically and throughout the entirety of the river.

One concept that kind of answers perhaps a different question is that current must be equal at all cross sectional points in a circuit. With this assumption, current cannot change after going through a resistor. Going back to an analogy of a circular river, water would eventually all pile up at the dam. But gravitation energy dictates that the most energetically favorable configuration is for water throughout the river to be even. Perhaps with a circuit, such a tendency for electrons to clump up would be countered by electric potential energy; the most energetically favorable configuration for electrons would be to have the greatest possible spacing. Thus, electric forces could in some sense transmit the holdup at the resistor throughout the entirety of the circuit.