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.