1) two semicircular filament have a common diameter. one lies in the x-y plane and one in the x-z plane. the curved portion of each carries a uniform line charge density (rho). find the electric filed at the common cetner of the semicircles?
2) A semicircular piece of wire carries density rho = (intial rho sin theta where theata = 0 at the midpoint of the wire ) , find the electric field at the center of circle ?
3) Find the electric field above a disc of radius r with uniform surface charge density s ?
4) Find the oscillatory frequency of a water molecule (with dipole moment p) displaced from equilibrium in a constant electric field E?