Like in RC (resistor-capacitor circuits) we have another combination circuit called an RL (resistor-inductance) circuit. Continuing this comparison to the RC circuit, capacitors, over time, went from ‘helping the circuit carry a current to ‘opposing. Counterintuitively inductors do the opposite: they begin by ‘opposing and end up ‘helping a current flow. The graphs of an RL circuit will not only teach you how to find the voltage and current at a point in time, but will also give you a mathematical/graphical representation of how an RL circuit looks over time (much like what we did with RC circuits). Of course, we can switch the resistor for a capacitor and make an LC circuit, which we cover in the next video.
When a circuit is first turned on, an inductor opposes current flow and acts like an open circuit. After a time, the inductor keeps the current going and acts like a short (like a wire).
If the battery is removed after the circuit has been on, the inductor acts like an emf source to keep the current going for a time. As the circuit dissipates power, the current will decay exponentially to zero.
To analyze an RL circuit, use Faraday’s Law. You cannot correctly use Kirchhoff’s Voltage Law (the loop rule) since the magnetic flux in the circuit is changing.
Lecture Slides are screen-captured images of important points in the lecture. Students can download and print out these lecture slide images to do practice problems as well as take notes while watching the lecture.
This book includes a comprehensive review of the key AP Physics C concepts and targeted strategies for acing every section of the exam. Additionally, the book includes two full length practice tests with full answer explanations.
The book offers a complete review of your AP course, strategies to give you the edge on test day, and plenty of practice with AP-style test questions. It includes 2 full length practice exams modeled on the real test, 3 separate plans to fit your study stle, review material updated to the most recent tests, and all the terms and concepts you need to know.