A charged particle having some mass is resting in equilibrium at a height `H` above the center of a uniformly charged non-conducting horizontal ring of radius ` R`. The equilibrium of the particle will be stable .

Three charged particles are collinear and are in equilibrium, then

A particle having no charge and no mass is

Find the electric field at the centre of a uniformly charged semicircular ring of radius R. Linear charge density is lamda

A charge -Q is unformly distributed over a non-conducting semi-circular rod of radius R . The potential at the center is

A charged particle of mass m having charge q remains in equilibrium at height d above a fixed charge Q . Now the charged particle is slightly displaced along the line joining the charges, show that it will executes S.H.M. and find the time period of oscillation.

A non conducting ring of radius R is charged as shown in figure : Figure

A small charged ball is hovering in the state of equilibrium at a height h over a very large horizontal uniformly charged sheet. If a disc of radius r (r lt lt h ) , is removed from the plate directly underneath the ball, then the acceleration of the ball will be

Charges q is uniformly distributed over a thin half ring of radius R . The electric field at the centre of the ring is

The nuclear particle having no mass and no charge, but only spin is