tldr: I am having trouble conceptually understanding voltage between resistors in series, even though I know how to calculate it using Ohm's law. How do the electrons "know" there are more resistors after going through the first one? Why doesn't it use up all the 10V so it's 10V -> resistor 1 -> 0V?
Case A: If a circuit has 1 resistor, the voltage on each side will be completely used up. For example, with a 10V battery and $5\Omega$ resistor, the voltage will be 10V -> resistor -> 0V, with a current of 2A.
Case B: However, if we attach another $5\Omega$ resistor, then the voltage will be 10V -> resistor 1 -> 5V -> resistor 2 -> 0, with a current of 1A.
From the perspective of the electrons, they don't know that there is another resistor down the line.
So why does the voltage drop across the first resistor 10V in Case A but only 5V in Case B?
I'm probably not understanding something very simple. This is my first circuits class and it's a lot to wrap my mind around! Thanks in advance.
Best Answer
The current is a moving ensemble of electrons, with a group drift velocity, no single electron goes from the positive to the negative pole of a battery. Electrons interact with the lattice and the molecules of the medium they pass through.
If they find a lot of resistance the drift velocity becomes lower, if the resistance is low the drift velocity becomes higher.No need for knowledge of the future path.
It is important to understand Ohm' law