Series Resistor Circuit

As the resistors are connected together in series the same current passes through each resistor in the chain and the total resistance, RT of the circuit must be equal to the sum of all the individual resistors added together. That is
![]()
Series Resistor Voltage
The voltage across each resistor connected in series follows different rules to that of the series current. We know from the above circuit that the total supply voltage across the resistors is equal to the sum of the potential differences across R1 , R2 and R3 , VAB = VR1 + VR2 + VR3 = 9V.
Using Ohm’s Law, the voltage across the individual resistors can be calculated as:
Voltage across R1 = IR1 = 1mA x 1kΩ = 1V
Voltage across R2 = IR2 = 1mA x 2kΩ = 2V
Voltage across R3 = IR3 = 1mA x 6kΩ = 6V
giving a total voltage VAB of ( 1V + 2V + 6V ) = 9V which is equal to the value of the supply voltage. Then the sum of the potential differences across the resistors is equal to the total potential difference across the combination and in our example this is 9V.

