1. A point charge +q is placed at the origin of an xy coordinate system, and a second point charge -2q is placed on the positive x-axis at a distance 3a from the origin. What is the electric field at the point (2a, 0)?

2. Two point charges of +2 μC and -5 μC are placed on the x-axis at positions x = 2 m and x = -3 m, respectively. What is the net electric field at the origin?

3. A uniform electric field E is directed along the positive x-axis. A point charge +3q is placed at the origin. What is the electric potential at a point P on the y-axis at a distance r from the origin?

4. Two point charges of +q and -2q are placed on the x-axis at positions x = a and x = -3a, respectively. What is the electric potential at the point (0, b)?

5. A point charge +q is placed at the origin and a second point charge +2q is placed on the positive x-axis at a distance a from the origin. What is the electric potential at the point (2a, 0)?

6. Two point charges of +3 μC and -5 μC are placed on the y-axis at positions y = 2 m and y = -3 m, respectively. What is the net electric field at the point (0, 0)?

7. A uniform electric field E is directed along the positive y-axis. A point charge -4q is placed at the origin. What is the electric potential at a point P on the x-axis at a distance r from the origin?

8. Two point charges of +q and -2q are placed on the y-axis at positions y = a and y = -3a, respectively. What is the electric field at the point (0, b)?

9. A point charge +q is placed at the origin and a second point charge +2q is placed on the y-axis at a distance a from the origin. What is the electric field at the point (2a, 0)?

10. Two point charges of +4 μC and -6 μC are placed on the x-axis at positions x = 2 m and x = -4 m, respectively. What is the net electric potential at the origin?