Question

Figure shows three charged circular arcs, each of radius $R,$ their centres are at same point and total charge as indicated. The net electric potential at the centre of curvature :-

• A. $\frac{Q}{2 \pi \epsilon _{0} R}$
• B. $\frac{5 Q}{12 \pi \epsilon _{0} R}$
• C. $\frac{3 Q}{32 \pi \epsilon _{0} R}$
• D. none of these

Answer 1

Answer: (A)

Charge can be considered as located at a distance
$R$ from the centre. Total charge is $\left(Q - 2 Q + 3 Q\right)$
Hence $V=\frac{1}{4 \pi \epsilon _{0}}\frac{2 Q}{R}=\frac{Q}{2 \pi \epsilon _{0} R}$