1. Quiz 2 Key SP212

2. Given: A positive point charge (+q) and a negative point charge (-q), are located at the opposite corners of a square of side length a. (a) Draw the pattern of electric field lines surrounding the two charges (5 pts). y axis x axis a a P

3. (b) Write an expression for the total electric field at point P, located at the top right corner, due to these charges. Leave your answer in terms of a, q and any required constants of nature (5pts). By the Principle of Superposition, the net E-field at point P is the sum of the contributions from +q and –q: Individually, +q and –q generate the following E-fields at point P: Therefore, the overall field at point P takes the form:

4. Bonus: What would be the electrostatic force felt by a neutron, if placed at point P? (1 pt) Electric fields only exert force on charged particles. Since a neutron has no net charge, it will experience no electrostatic force at point P.