A current of $2 \mathrm{~A}$ flows in an electric circuit as shown in figure. The potential difference…
A current of $2 \mathrm{~A}$ flows in an electric circuit as shown in figure. The potential difference $\left(V_R-V_S\right)$, in volts $\left(V_R\right.$ and $V_S$ are potentials at $R$ and $S$ respectively) is
$-4$
$+2$
$+4$
$-2$
Solution
Current through each arm
$
\begin{gathered}
P R Q \text { and } P S Q=1 \mathrm{~A} \\
V_P-V_R=3 \mathrm{~V} \\
V_P-V_S=7 \mathrm{~V}
\end{gathered}
$
From Eqs. (i) and (ii), we get
$
V_R-V_S=+4 \mathrm{~V}
$
