Energy systems


1. Light & Sound


This lesson begins by revisiting the classic Batteries and Bulbs unit: students try to make a coin battery light up a LED and turn on a buzzer. Once they have addressed these basic challenges, students can explore lighting up two LED’s, or an LED and a buzzer, in parallel and/or series combinations. The Penguin Race toy is available to provide models of current, voltage, source and load.

Advance Preparation


  • LED’s – 10 per group (assorted colors)
  • Buzzer – one per student
  • Coin battery – one per student
  • The Penguin Race toy – one per class
  • Worksheets: Light & Sound and Switch Hunt (downloadable at bottom of page)


  1. Electricity Concepts: Lead a brief review of electric circuits. If students have already done “Batteries and Bulbs” you can use this experience as a starting point (see a video). Another way to illustrate electricity is by demonstrating and discussing the Penguin Race Toy (video). Develop the idea that this toy is a model of a circuit.

  2. Different kinds of batteries and bulbs: Distribute LED’s and coin batteries. Ask students to examine them carefully (video) and notice and record differences from batteries and bulbs they have seen before.

  3. Light the LED and sound the buzzer: Challenge students to light the LED (video) and record how they did it. Then distribute buzzers, and challenge students to make it sound off (video).

  4. Batteries and Loads: Introduce the term load for a LED, buzzer or anything else that runs from battery (video). Then ask students to experiment with more than one LED or an LED and a buzzer, and/or more than one battery (video).

Homework: Switch hunt. Provide the Switch Hunt Worksheet (downloadable below). Ask students to look for switches at home, and use the worksheet o describe where they found them, what they control and what they operate. See Lesson 2 for a typical list.


To learn about how LED’s work together, you can use a Digital Multi meter (see video). For example, the Multi meter will show you why a red or yellow LED will turn a green or blue one off, when they are both connected to the same battery. More information about the Digital Multi meter is available in the Appendix to ElectroCity.