Find the field from potential The electric field points along the shortest direction from one equipotential surface to the next one. U+dU dAb=q.0-(0+dU】=gEd -dU E cos0 dl d E cos0=E=- dl Find the field from potential U U+dU E  a b  The electric field points along the shortest direction from one equipotential surface to the next one. dl dU E cos  El  