Points A and B lie within a region of space where there is
a uniform electric field that has no x- or z-component;
only the y-component Ey is nonzero. Point A is at
y = 8. 00 cm and point B is at y = 15. 0 cm. The potential
difference between B and A is V_B - V_A= +12. 0 V, so
point B is at higher potential than point A.