Current Division Rule
A parallel circuit acts as a current divider as the current divides in all the branches in a parallel circuit, and the voltage remains the same across them. The current division rule determines the current across the circuit impedance. The current division is explained with the help of the circuit shown below:
As we know,
V = IR ……..(1)
Equation (1) can also be written as:
I = V/R ……….(3)
Now, putting the value of R from the equation (2) in the equation (3) we will get
Thus, in the current division rule, it is said that the current in any of the parallel branches is equal to the ratio of opposite branch resistance to the total resistance, multiplied by the total current.
Voltage Division Rule
The voltage division rule can be understood by considering a series circuit shown below. In a series circuit, voltage is divided, whereas the current remains the same.
As we know,
I = V/R or we can say I = E/R
Thus, the voltage across a resistor in a series circuit is equal to the value of that resistor times the total impressed voltage across the series elements divided by the total resistance of the series elements.