No matter the arrangement of resistors in a circuit, a battery will still produce a current as if it were connected to an imaginary combination of the individual resistors within the circuit? Can anyone explain why this is so, can the charged particles know there is a resistance before they leave the power supply? I know similar questions has been asked, but this has a minor detail which was neither asked nor answered. I am wondering why the total current within a circuit is calculated based on Req, if resistances don't affect the current? I=V/R? Current is charge per unit time, but nobody talks about the time factor affecting the current, I know that the number of particles within a series circuit will be the same, but why is the current same?Do the particles know that there will be resistance before they even reach it?
No particles do not know this .Let a batterry is connected with a parallel arrangement of resistors with resistors R1 and R2 as and R1>R2 . This means that R1 have greater resistance for current. Now when the battery is connected then due to potential differebce some of the electrons which are weakly attracted by the nucleaus gets detached from it and started moving towards higher potential.To maintain electrical neutrality battery provides the electrons to those atoms.Now we can understand from here that more resistance means that they have less number of weakly held electrons this implies their will be less movement of charge in direction of potential difference and hence less current. About time factor we can say that drift velocity of electron =eEt/m Here we can see that it mainly depends on electric field and average relaxation .