*49%*:**Examining students' understanding of electrical circuits through multiple-choice testing and interviews***46%*:**Students' understanding of direct current resistive electrical circuits***45%*:**Conceptual Understanding of Resistive Electric Circuits Among First-year Engineering Students***42%*:**Teaching Electric Circuit Concepts Using Microcomputer-Based Current/Voltage Probes***41%*:**PhET Simulation: Circuit Construction Kit (DC Only)***39%*:**PhET Teacher Ideas and Activities: Properties of Electric Circuits Using Only Circuit Construction Kit (CCK)***36%*:**DC Circuits***35%*:**Force Concept Inventory-based multiple-choice test for investigating students' representational consistency***35%*:**Multiple-choice test of energy and momentum concepts***35%*:**Testing Studentsâ€™ Understanding of Vector Concepts***35%*:**Dividing the Force Concept Inventory into two equivalent half-length tests***32%*:**PhET Simulation: Circuit Construction Kit (AC+DC)***32%*:**Cirque du Circuit: A Unit on Electric Circuits for High School Physics***32%*:**Context Rich Problems Online Archives: Circuits Problems***31%*:**Test of understanding of vectors: A reliable multiple-choice vector concept test***31%*:**Connecting Concepts About Current to Quantitative Circuit Problems***31%*:**Mag Lab U: Interactive Tutorials - Current Flow***31%*:**Quantum Mechanics Survey (QMS)***30%*:**PhET Simulation: Battery-Resistor Circuit**