Question 72486
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I think you mean the resistors in parallel formula which is:
{{{1/((1/R1)+(1/R2))}}}
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When there are only two resistors in parallel, it can be simplified:
Put the denominator fraction over a common denominator:
{{{1/((R1 + R2)/(R1*R2))}}}
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When you divide by a fraction, you invert and multiply:
1 * {{{((R1*R2)/(R1+R2))}}}
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Or just: {{{((R1*R2)/(R1+R2))}}}
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The "product over sum" equation universally used for two resistors in parallel
:
For example if you had R1 = 30 ohms and R1 = 70 ohms
Rt = {{{((30*70)/(30+70))}}}
Rt = {{{((2100)/(100))}}}
Rt = 21 ohms