Question

A uniform electric field E=10 V/m points in the x direction as shown in the Figure. Point A has coordinates (0,1m) and point B has coordinated (2m,2m), where points are labeled according to P=(x,y). What is the potential difference V_B-V_A (in Volts)?

Answer 1

The potential difference is equal to the following line integral,

where I have chosen the path shown in the Figure. Evaluating the line integral along AC gives zero since E is perpendicular to the path and along the path CB E is parallel to the path so that,

and hence VB-VA = -20V.