Question

A current of 2 A flows in an electric circuit as shown in figure. The potential difference (VR – VS) , in volts (VR and VS are potentials at R and S respectively) is

Answer 1

12/11

Answer 2

The three resistors (3 Ω, 2 Ω, 1 Ω) are in parallel between points R and S.

The equivalent resistance is $R_{eq} = (\frac{1}{3} + \frac{1}{2} + \frac{1}{1})^{-1} = (\frac{2+3+6}{6})^{-1} = (\frac{11}{6})^{-1} = \frac{6}{11} \, \Omega$.

The total current through the parallel combination is $I = 2 \, A$.

The potential difference is $V_R - V_S = I \times R_{eq} = 2 \, A \times \frac{6}{11} \, \Omega = \frac{12}{11} \, V$.