Which of the following correctly gives the equivalent resistance of three resistors…

PHYSICS · Single correct · A Level · Physics · Electricity · Electricity

Problem

Which of the following correctly gives the equivalent resistance

R_{\text{eq}}

of three resistors

R_1,\,R_2,\,R_3

connected in parallel? (a)

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

(b)

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

(c)

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

(d)

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