CBSE Class 10 Answered

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 ,  V_AB = V_R1 + V_R2 + V_R3 = 9V.

Using Ohm's Law, the voltage across the individual resistors can be calculated as:

Voltage across R₁ = IR₁ =  1mA x 1k? = 1V

Voltage across R₂ = IR₂ =  1mA x 2k? = 2V

Voltage across R₃ = IR₃ =  1mA x 6k? = 6V

giving a total voltage V_AB 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.

The equation given for calculating the total voltage in a series circuit which is the sum of all the individual voltages added together is given as:

Then series resistor networks can also be thought of as "voltage dividers" and a series resistor circuit having N resistive components will have N-different voltages across it while maintaining a common current.

By using Ohm's Law, either the voltage, current or resistance of any series connected circuit can easily be found and resistor of a series circuit can be interchanged without affecting the total resistance, current, or power to each resistor.