BASIC ELECTRONICS - OD1633 - LESSON 1/TASK 2
Convert the fractions to a common denominator.
Since both sides are reciprocals (each divided is into owe), disregard the
The formula for equal resistors in parallel,
is a simplification
of the general formula for resistors in parallel.
There are other
simplifications of the general formula for resistors in parallel which can
be used to calculate the total or equivalent resistance in a parallel
(a) Reciprocal Method.
This method is based upon taking the
reciprocal of each side of the equation. This presents the general formula
for resistors in parallel as:
This formula is used to solve for the equivalent resistance of a number of
unequal parallel resistors. You must find the lowest common denominator in
solving these problems.
Example: Three resistors are connected in parallel as shown in figure 51 (on
the following page). The resistor values are: R1 = 20 Ohms, R2 = 30 Ohms,
R3 = 40 Ohms.
Using the reciprocal method, what is the equivalent