Electrical Potential Energy of a System of Two Point Charges and of Electric Dipole in an Electrostatic Field

A point charge q₀ is moving along a circular path of radius a, with a point charge Q at the centre of the circle. The kinetic energy of q₀ is ______.

Three-point charges Q, q and -q are kept at the vertices of an equilateral triangle of side L as shown in the figure. What is 

1. the electrostatic potential energy of the arrangement? and
2. the potential at point D?

Obtain an expression for an intensity of electric field at a point at the end of position, i.e., the axial position of an electric dipole.

x

Why must electrostatic field be normal to the surface at every point of a charged conductor?

A small test charge is released at rest at a point in an electrostatic field configuration. Will it travel along the field line passing through that point?

Three point charges, + Q + 2Q and – 3Q are placed at the vertices of an equilateral triangle ABC of side l. If these charges are displaced to the mid-point A₁, B₁ and C₁, respectively, find the amount of the work done in shifting the charges to the new locations.

In a hydrogen atom, the electron and proton are bound at a distance of about 0.53 Å:

(a) Estimate the potential energy of the system in eV, taking the zero of the potential energy at infinite separation of the electron from proton.

(b) What is the minimum work required to free the electron, given that its kinetic energy in the orbit is half the magnitude of potential energy obtained in (a)?

(c) What are the answers to (a) and (b) above if the zero of potential energy is taken at 1.06 Å separation?

Guess a possible reason why water has a much greater dielectric constant (= 80) than say, mica (= 6).