Two point charges qa and qb are located on the x-axis at x = a and x = b. FIGURE EX25.34 is a graph of V, the electric potential. a. What are the signs of qa and qb? b. What is the ratio qa/qb ? c. Draw a graph of Ex, the x-component of the electric field, as a function of x.

Week 5 Tuesday, September 20, 2016 11:13 AM Potentials and charged conductors ○ Vsurface= Wab=- PE All points on surface of charged conductor in electrostatic eq are at same potential Electric potential constant everywhere on surface and equal to inside value Eqiupotential surfaces- surface on which all points are at same potential V=Vb-Va=0 Wab= - PE=-q V=0 No work needed to move chrge at constant speed on equipot surface Electric field is perpendicular to equipot surface Equipot & EF lines Equipot- family of spheres centered on point charge Potential dec along direction of EF lines EF lines perpendicular to E pot