I know the battery in a circuit, is the sole source of potential, but why is it
ID: 1531458 • Letter: I
Question
I know the battery in a circuit, is the sole source of potential, but why is it that when I have resistors in a series on the circuit, the potential difference across each individual resistor when summed, is equal to the potential difference across the battery? Example: Vr1 + Vr2 + Vr3 = Vbattery
Moreover, why is it that when I change the quantity of resistors or their individual strength, they still equal the same potential difference across the battery?
Example: the potential difference across a battery = 2.5V the potential difference across the 325ohm resistor in the circuit is 2.5V. If another 325ohm resistor is added, the potential difference across both resistors now becomes 1.25V.
Explanation / Answer
When we have three resistors connected in series and a battery across them,then the current flowing along each resistor will be same (Let I).
But each resistor may have same or different values.
potential difference across 1 resistor ,from ohm's law,V1 = I*R1
potential difference across 2 resistor,V2 = I*R2
potential difference across 3 resistor,V3 = I*R3
since in series current remain same so potential divides across each resistor in order to have same current across each resistor.that's why we have
potential difference across battery , V= I*R1 + I*R2 +I*R3