The Workshop Physics Activity Guide is a set of student workbooks designed to serve as the foundation for a two-semester calculus-based introductory physics course. It consists of four Modules, with a total of 28 units, that interweave text materials with activities that include prediction, qualitative observation, explanation, equation derivation, mathematical modeling, quantitative experiments, and problem solving. The modules help students understand the basis of knowledge in physics as interplay between observations, experiments, definitions, and mathematical theory. The inquiry-based activities in the modules give students the opportunity to work collaboratively to solve problems, while thinking critically to make predictions and observations. Students use a powerful set of computer tools to record, display, and analyze data, as well as to develop mathematical models of physical phenomena. The design of many of the activities is based on the outcomes of physics education research. Module 4 Unit 19 Electric Forces and FieldsUnit 20 Electric Flux and Gauss' LawUnit 21 Electric PotentialUnit 22 Introduction to Electric CircuitsUnit 23 Circuit AnalysisUnit 24 Capacitors and RC CircuitsUnit 25 ElectronicsUnit 26 Magnets and Magnetic FieldsUnit 27 Electricity and Magnetism