
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
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



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














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






