Electric Field & Field Lines question from JEE Main 2025 (4 Apr, Shift 2)

Answer: (d)

1. Quarter arc AB gives field $E$ at O along the bisector of AB (pointing away from the arc).
2. Arc ABC = arc AB + arc BC; arc BC gives an equal field $E$ along its own bisector.
3. The two bisectors are $90^\circ$ apart, so $E_{net} = \sqrt{E^2 + E^2} = \sqrt{2}E$.
4. So the answer is (d) $\sqrt{2}E$.