PROBLEM 1 If Q = 16 nC, a = = 3.0 m, and b = 4.0 m, what is the magnitude of the electric field at point P? P 90 e ANS: 24 N/C PROBLEM 2 A+15-nC point charge is placed on the x axis at x = 1.5 m, and a -20-nC charge is placed on the y axis at y = -2.0m. What is the magnitude of the electric field at the origin? ANS: 75 N/C = 4.0 cm. PROBLEM 3 A 40-mC charge is positioned on the x axis at x = Where should a -60-mC charge be placed to produce a net electric field of zero at the origin? ANS: 4.9 cm