[" Find the electric field strength vector at the centre of a ball of radius R with volume density "rho=ar" where a is a constant "],[" vector,and ris a radius vector drawn firon the ball's centre."]

Find the electric field strength vector at the centre of a ball of raiduius R with volume charge density rho implies ar , where a is a constant vector, and r is a radius vector drawn from the ball's centre.

Find the electric field strength vector if the potentail of this field has the form varphi = ar , where is a constatn vector, and r is the radius vector of point of the field.

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

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

A system consits of a ball of radus R carrying spherically symmetric charge and the surrounding space filled with a charge of volume density rho = alpha//r , wehre alpha is a constant, r is the distance from the centre of the ball. Find the ball's the charge at whcih the magnitude of the electric field strength vector is independent of r outside the ball. How high is this strength ? The permittives of the ball and the surrounding space are assumed to be equal to unity.

A system consists of a ball of radius R carrying a uniformly distributed charge q and the surrounding space filled with a charge of volume density rho = alpha//r , where alpha is a constant and r is the distance from the centre of the ball. Find the charge on the ball for which the magnitude of electric field strength outside the ball is constant? The dielectric constant of the ball and the surrounding may be taken equal to unity.

An insulating solid sphere of the radius R is charged in a non - uniform manner such that the volume charge density rho=(A)/(r ) , where A is a positive constant and r is the distance from the centre. The potential difference between the centre and surface of the sphere is

An insulating solid sphere of the radius R is charged in a non - uniform manner such that the volume charge density rho=(A)/(r ) , where A is a positive constant and r is the distance from the centre. The potential difference between the centre and surface of the sphere is