
An annular disc has inner and outer radius and . Surface density of charge is . The electric field at any point at a distance along the axis of the disc is given by

Important Questions on Interaction of Charged Particles, Electric Field and Potential
















Three charged particles and with charges and are present on the circumference of a circle of radius The charged particles and centre of the circle formed an equilateral triangle as shown in the figure. The electric field at the point is


Four point charges are located at the corners of a square of side The force acting on a charge of placed at centre of the square is



A thin disc of radius has a concentric hole of radius in it (see figure). It carries uniform surface charge on it. If the electric field on its axis at a height from its centre is given as then the value of is

A uniform electric field, is applied in a region. A charged particle of mass carrying positive charge is projected in this region with an initial speed of . This particle is aimed to hit a target , which is away from its entry point into the field as shown schematically in the figure. Take . Then

