# Resistors in series and current equivalence.

1. May 25, 2014

### Prashasti

"Resistors resist the passage of current through them." Then why the current through each resistor same in series combination? Suppose 'I' current is passing through a system of two resistors connected in series.
1. Won't the first resistor - which is directly connected to the positive terminal of the battery - allow a current with less magnitude to pass through, as compared to the original current with magnitude 'I'?

2. And that the second resistor will not get the current with magnitude 'I'- rather- something of lesser value?

2. May 25, 2014

### UltrafastPED

Series looks like: ------[R1]-------[R2]------

Since the current entering on the left is just a bunch of moving charges (electrons), where would the electrons go if they didn't continue on through to the end?

If they didn't the individual resistors would be accumulating charge, and would be called capacitors!

They call it an electric current because it behaves similar to the flow of water: what comes in must go out.

What is changing is the voltage: there is a drop in voltage of V1 = I*R1 as the current flows through R1, and
V2 = I*R2 when it flows through R2. Kirchoff noted that the voltage drop around a loop is always zero - the battery supplies an initial voltage at one terminal (usually +), so V_battery = V1 + V2 if we close the above loop with a battery.

Kirchoff's second rule notes that the current flowing into a junction is equal to the current flowing out of a junction; if there is no junction then the current is unchanged.