Fair game for quizzes in discussion sections includes any material that has been covered up through the homework that will be due at the NEXT discussion section. The lessons on electric forces and fields, and electric potential and potential energy, will be very helpful in forming a conceptual understanding of the material presented in class on chapters 16 and 17. You may see problems like these on quizzes or exams. In addition to conceptual questions from previous years, the MCAT practice questions on the Giancoli web page also offer more practice answering conceptual questions. Other resources To gain a conceptual understanding of electric fields and potentials, try these lessons on E-fields and potentials by Andrew Duffy and Ali Loewy of the BU Physics Department.
Electric fields can be tricky things to understand.
Try this simulation of electric fields. Here are also a couple of magnetic field simulations. The first focuses on long straight wires and the second deals with coils and solenoids . Here is an explanation of the right-hand rule for determining the directions of the velocity, magnetic field, and force on a charge vectors. There is also a simulation of AC Circuits .