RedCrab Math Tutorial


Resistor and Conductance
Ohm's Law
Specific Resistivity and Conductance
Resistors in Series
Resistors in Parallel
Wire Voltage Loss
Electrical Power



Resistors in Parallel

If the current in a circuit is distributed over several resistors we call this a parallel circuit of resistors. There is the same voltage across all resistors
If the total current and voltage are known, we can calculate the total resistance according to Ohm's law from the following formula:
If the values of current or voltage are unknown, we can add the conductivities of the individual resistors
Example with three resistors of 220, 330 and 470 Ohm

For a circuit in which two resistors are connected in parallel, we can change to a simpler formula by adding the two fractions:
This results in:
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