BASIC DC CIRCUIT CALCULATIONS
Basic DC Theory
Current Division
Sometimes it is necessary to find the individual branch currents in a parallel circuit when only
resistance and total current are known. When only two branches are involved, the current in one
branch will be some fraction of IT. The resistance in each circuit can be used to divide the total
current into fractional currents in each branch. This process is known as current division.
(2-13)
I1
R2
R1
R2
IT
I2
R1
R1
R2
IT
Note that the equation for each branch current has the opposite R in the numerator. This is
because each branch current is inversely proportional to the branch resistance.
Example:
Find branch current for I1 and I2 for the circuit shown in Figure 30.
Figure 30 Current Division Example Circuit
ES-02
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