In this lab students measure the resistance of various twinkle lights; individually at first and then in combination. They learn how to set up a multimeter as an ohmmeter and to use it for this purpose. Students demonstrate that resistance is cumulative when placed in series. Extension ideas have students measure the resistance of a few lights connected in parallel where they can see that the resistance of the lights drops dramatically. This activity gives experience with series circuits and begins to introduce the idea of parallel circuits. Students are asked to draw a simple circuit diagram showing their setup.
♦ When lights are placed in series, their resistance adds
♦ Resistance is measured using an ohmmeter or multimeter
♦ When placed in series; two lights have twice the resistance of one and so on
♦ When lights are placed in series, their brightness dims
multimeter, 3+ twinkle lights, 2 alligator clips
Time Required This lab takes about 40 mins.
Student Sheets • Scaffolded writing prompts & lab reporting
Answer Keys and Teacher Notes address most questions and issues that might arise in this study—you shouldn’t have to do any outside research unless you want to.
Connect with me: If you have questions or problems, please let me know and I’ll get back to you as soon as I can.
This resource (along with all resources sold on this site) can be found inside the membership. For information on that option, click here.