question_answer

  Point charge q moves from point P to point S along the path PQRS (as shown in fig.) in a uniform electric field E pointing co-parallel to the positive direction of X-axis. The coordinates 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 case is given by the expression

A) \[qEA\]

B) \[-qEA\]

C) \[qEA\sqrt{2}\]

D) \[qE\sqrt{\left[ {{\left( 2a \right)}^{2}}+{{b}^{2}} \right]}\]