Now build the complete circuit. Connect a wire to each end of the pair of batteries. Then add the lightbulb and the switch, using additional wires as needed. To disconnect two parts, click where they’re joined, and then click Split Junction. You can also click Reset All to start over. You’ll be successful when you can close the switch (click, hold, and drag it) and the lightbulb glows. Use the drawing tool to sketch the parts of your successful circuit.