Five positive charges each having charge q are placed at the vertices of a pentagon as shown in the figure. The electric potential (V) and the electric field (E) at the center O of the pentagon due to these five positive charges are:
(A)V=4πε0r5q and E=0✓ Correct
(B)V=4πε0r5q and E=8πε0r253qr^
(C)V=4πε0r5q and E=4πε0r25qr^
(D)V=0 and E=0
Answer: (A)
Solution
Potential is a scalar, so the five charges add directly: V=5⋅4πε01rq=4πε0r5q. The field is a vector; the five equal charges occupy the vertices of a regular pentagon, so the five field contributions at the centre are equal in magnitude and separated by 72∘, and their vector sum is zero. Thus V=4πε0r5q and E=0.
JEE Main · 2026 · 22 Jan 2026 · Shift 2 · Single correct option