MEL TECH
CIRCTRONICS
Current Divider Theorem
The Current Divider Theorem or Rule is usefull in determining the current through one branch of a parallel circuit.
The General Formula:
Where:
Ix - current in any of the resistors in the circuit
It - total current or current source of the circuit
Rx - the resistor concerned
Rt - the equivalent resistance of the parallel circuit
For Two Resistors in Parallel:
I1 = It (R2)
R1 +R2
I2 = It (R1)
R1 +R2
Tips
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If solving Series-Parallel circuits, solve the Parallel parts first, then you are left with only a much-easier Series circuit.
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At each step, write down the given values such as voltage, current, resistance.
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The sum of the individual currents will equal the total current It=I1+I2+I3...
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In parallel circuits and series-parallel, you will often find "t" added to any of these symbols, in which case it represents Total, meaning the voltage, current, or resistance of the circuit when considered as a whole.
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The sum of the individual Powers will equal the total power Pt=P1+P2...
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In a Parallel circuit the same voltage is applied across all the resistors.
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Use the examples in your notes to help you solve the unknown values in the following circuits. Don't forget to include units with your answers.
Example:
