A point charge of +8.0μC is fixed at the origin, and a point charge of +2.0μC is fixed at x=0.50m. (a) Determine the distance to the right of the +2.0μC charge at which a small positive test charge would experience zero net electric field produced by the two fixed charges. (b) State whether any additional null points exist between the two charges. Provide both answers with brief justification.