Physics

Problem

Which of the following gives the equivalent resistance

R_{\text{eq}}

of three resistors

R_1,\,R_2,\,R_3

connected in series? a)

\displaystyle R_{\text{eq}} = \frac{R_1+R_2+R_3}{3}

\displaystyle R_{\text{eq}} = \left( \frac{1}{R_1}+\frac{1}{R_2}+\frac{1}{R_3} \right)^{-1}

\displaystyle R_{\text{eq}} = R_1 + R_2 + R_3

\displaystyle R_{\text{eq}} = \frac{1}{R_1}+\frac{1}{R_2}+\frac{1}{R_3}