A metallic ring is uniformly charged as shown in figure. AC and BD are two mutually perpendicular diameters. Electric field due to arcAB to ' O ' is ' E ' is magnitude. What would be the magnitude of electric field at ' O ' due to arcABC ?
(A)2E
(B)2E✓ Correct
(C)E/2
(D)Zero
Answer: (B)
Solution
Each quarter arc of the uniformly charged ring produces a field of magnitude E at the centre, directed along the bisector of that arc. The half ring ABC is made of the two adjacent quarter arcs AB and BC, whose field directions at the centre are mutually perpendicular. Adding these two equal and perpendicular contributions, the field at the centre due to arc ABC has magnitude E2+E2=2E.
JEE Main · 2025 · 04 Apr 2025 · Shift 2 · Single correct option