Question

A current of $2 \,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

• A. −4
• B. +2
• C. +4
• D. −2

Answer 1

Answer: (C)

Current through each arm
$P R Q$ and $ P S Q=1\, A$
$V_{P}-V_{R}=3\, V\,\,\,...(i)$
$V_{P}-V_{S}=7 \, V\,\,\,...(ii)$
From Eqs. (i) and (ii), we get
$V_{R}-V_{S}=+4\, V$