This document provides a summary of key concepts in electric circuits for an AP Physics exam. It defines important terms like charge, current, voltage, and resistance. It explains the differences between series and parallel circuits and introduces Kirchhoff's laws. Formulas for voltage, resistance, power, and circuit calculations are presented. Example problems demonstrate applying the concepts and formulas to calculate current, power usage, and the number of light bulbs that can be connected before tripping a circuit breaker.