Question

What is the equivalent resistance in a parallel circuit if there are three resistors of values 3.00, 4.00, and 5.00?0.7830.0833312.00Ω1.28

Answer 1

Formula for calculating equivalent circuit is,

$\begin{gathered} \frac{1}{Req}=\frac{1}{R1}+\frac{1}{R2}+\frac{1}{R3} \\ Where, \\ Req=Equivalent\text{ }Resistance \\ R1=3\Omega \\ R2=4\Omega \\ R3=5\Omega \end{gathered}$

So,

$\begin{gathered} \frac{1}{Req}=\frac{1}{3}+\frac{1}{4}+\frac{1}{5}=\frac{(4\times5)+(3\times5)+(3\times4)}{60}=\frac{20+15+12}{60} \\ \frac{1}{Req}=\frac{47}{60} \\ So, \\ Req=\frac{60}{47} \\ Req=1.276\Omega \\ Which\text{ }is\text{ }close\text{ }to\text{ }1.28\Omega \end{gathered}$

So 4th option is correct option.