A Van de Graaff generator used for classroom demonstrations has a conducting spherical dome with a radius of 15 cm. The electric potential produced by the charged generator is -8.5 x 10* Vnear its surface. The sphere has a uniform distribution of charge, so you may assume that all charge on the sphere is concentrated at the sphere's centre.Assume that the electric potential at a large distance and at Earth's surface is zero. KU TA A (a) Calculate the charge on the sphere. (b) Calculate the magnitude of the electric field near the surface of the sphere. (c) In which direction does the electric field point?