1. The problem statement, all variables and given/known data Which point in the electric field in the diagram is at the lowest potential? Figure: http://i131.photobucket.com/albums/p289/SoaringCrane/Tip24_fig3.gif a.Point 1 b.Point 2 c.Point 3 d.Point 4 e.Point 5 2. Relevant equations See below. 3. The attempt at a solution Equipotential lines are perpendicular to electric field lines, so dots in the same column have the same potential. Electric field lines go from high voltage to low voltage, so dots at the near right have the lowest potential? Rightmost is Point 3? 1. The problem statement, all variables and given/known data Charges Q and q (Q is not equal to q), separated by a distance d, produce a potential V_p at point P. Figure: http://i131.photobucket.com/albums/p289/SoaringCrane/Tip24_fig1.gif This means that a.no force is acting on a test charge placed at point P. b.Q and q must have the same sign. c.the electric field must be zero at point P. d.the net work in bringing Q to a distance d from q is zero. e.the net work needed to bring a charge from infinity to point P is zero. 2. Relevant equations See below. 3. The attempt at a solution Following the fact that V/m = N/C, the electric field will also be 0??? 1. The problem statement, all variables and given/known data Charges +Q and -Q are arranged at the corners of a square as shown. Figure: http://i131.photobucket.com/albums/p289/SoaringCrane/Tip24_fig2.gif When the electric field and the electric potential V are determined at P, the center of the square, we find that a. E no equal 0; V>0 b. E = 0; V = 0 c. E = 0; V>0 d. E no equal 0; V<0 2. Relevant equations See below. 3. The attempt at a solution Well, if the vectors are drawn from the center, they cancel out so E = 0. If E=0, then wouldn’t the potential also be 0? Thanks.