question_answer

A point charge q moves from point P to point S along the path PQRS in a uniform electric field E pointing parallel to the positive direction of the x-axis, the coordinate of the points P,Q,R and S are \[(a,b,0)\,\,(2a,0,0),\,(a-b,0)\] and \[(0,0,0)\] respectively. The work done by the field in the above process is given by the expression:            

A)  \[qaE\]               

B)  \[-qaE\]

C)  \[q\sqrt{({{a}^{2}}+{{b}^{2}})}E\]           

D)  \[3qE\sqrt{{{a}^{2}}+{{b}^{2}}}\]