Multiple-Choice Homework Problem 3.1 [3 pt(s) ] A negatively charged particle is fixed at the origin. What is the direction of the electric field at a point along the positive x axis
For a negatively charged particle the direction electric field lines is always into the charge. So, when a negative charge is placed on the origin then the direction of the electric field lines will be 180° to the positive x-axis, i.e. the field lines will be travelling from infinity towards the origin.
Contrary to this the positive charges have the direction of electric field lines emerging out from the charge.