A uniform electric field of magnitude 5 x 103 N/C is directed along the negative x-direction. Co-ordinates of point A in the Fig. 2.134 are (-40 cm,+ 20 cm) and those of point Bare (20 cm, -60 cm). Potential difference between A and B, i.e., VA-VB along the arc of a circle of radius 2 m is :