Which expression gives the equivalent resistance of three resistors and connected in…

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

Problem

Which expression gives the equivalent resistance

R_{\text{eq}}

of three resistors

R_1, R_2,

and

R_3

connected in parallel? (a)

R_{\text{eq}} = \dfrac{R_1R_2+R_2R_3+R_3R_1}{R_1R_2R_3}

(b)

R_{\text{eq}} = \dfrac{R_1R_2}{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)

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