A charge water drop of radius `r` is in equilibrium in an electric field. If chare on it is equal to chare of an electron, then intensity of electric field will be : ( Density of water = `rho`, assume gravity)

Three eqal charges +Q each are at the corners of an equilibrium triangle as shown. The intensity of electric field at O will be

There are n electrons of charge on a drop of oil of density rho . It is in equilibrium in an electric field E. Then radius of drop is

An isolated solid metal sphere of radius R is given an electric charge. The variation of the intensity of the electric field with the distance r from the centre of the sphere is best shown by

A charges particles particle is kept in equilibrium in the electric field between the plates of millikan oil drop experiment. If the direction of the electric field between the plates is reversed, then calculate acceleration of the charged particle.

a proton placed in an electric field would experience an electrical force equal to its weight. the magnitude of electric field intensity E would be

The force experienced by a charge of 2mu C in an electric field is 3 xx 10^(-3)N . The intensity of the electric field.

Intensity of an electric field (E) depends on distance r due to a dipole, is related as

A spherical shell of radius R has a uniformly distributed charge ,then electric field varies as

If E is the electric field intensity of an electrostatic field, then the electrostatic energy density is proportional to

The electric field at distance .r. from infinte line of charge ("having linear charge density" lambda) is