Problem Solving. Show your pertinent solution and BOX your final answer. 1. An infinite plane sheet of charge produces an electric field with a magnitude of 4.50 N/C. What must be its charge per unit area (in coulombs per square meter)? 2. The charge per unit length of a long straight wire is 3.00 x 10 -12 C/m. Calculate the distance from the wire where the electric field is measured to be 0.600 N/C. 3. Calculate the number of excess electrons that must be added to an isolated spherical conductor (diameter = 0.100m) to generate an electric field of 1800 N/C just outside its surface