Question

If the potential difference between $A$ and $D$ is $V$, what will be potential difference between $F$ and $C$. Each of the resistance is $R$.

• A. V/3
• B. V/4
• C. V/6
• D. V/8

Answer 1

Answer: (B)

$V=I R_{ eq }=I \frac{4 R}{3}$
or $I=\frac{3 V}{4 R}$.
$V_{1}=V_{A}-V_{F}=I \frac{R}{2}$
$V_{2}=V_{A}-V_{C}=I\left(\frac{R}{2}+\frac{R}{3}\right)=\frac{5}{6} I R$
$V_{2}-V_{1}=V_{F}-V_{C}=I R\left(\frac{5}{6}-\frac{1}{2}\right)=\frac{I R}{3}$
$V_{F}-V_{C}=\frac{I R}{3}=\left(\frac{4 I R}{3}\right) \frac{1}{4}=\frac{V}{4}$