Energy conservation in electric field

2026 Re-NEET 1 question

1. Consider a fixed uniformly charged insulating sphere with radius R and total charge +Q. A point charge -q (q << Q) with mass m is released from rest at a distance of 3R from the centre of the charged sphere. When the point charge reaches the surface of the sphere, its speed is: ($\varepsilon_0$ is the permittivity of vacuum, neglect gravitational forces).