Why Don't Paper Circuits Need Resistors for LEDs?

Paper circuits are a popular type of project that use 3V coin cell batteries and copper tape instead of AA batteries and a breadboard to build a circuit. However, they don't need current-limiting resistors with LEDs! If you've ever built circuits with LEDs before, you know current-limiting resistors are a must in order to avoid burning out your LED. This video explains the concept of battery internal resistance and how it applies to these two different type of circuits. For directions to make your own paper circuit: https://www.sciencebuddies.org/stem-a... For instructions on how to build a circuit on a breadboard: https://www.sciencebuddies.org/scienc... Science Buddies also hosts a library of instructions for over 1,500 other hands-on science projects, lesson plans, and fun activities for K-12 parents, students, and teachers! Visit us at https://www.sciencebuddies.org/?ytid=... to learn more. #STEM #sciencebuddies ******************************* Connect with Science Buddies: TWITTER:   / sciencebuddies   FACEBOOK:   / sciencebuddies   INSTAGRAM:   / scibuddy   PINTEREST:   / sciencebuddies