Explanation

(a) The figure shows the path of a $+ ve$ charged particle (1) through a rectangular region of uniform electric field.
[image:1_image368.emf]
Since, $+ ve$ charged particle moves as a parabolic path in electric field, it means the direction of electric field is upward. The direction of particle (2) which is $- ve$ is downward.
The direction of deflection of particle (3) which is $+ ve$ is upward and direction of deflection of particle (4) is downward