Teaching Notes

You may have to assist some groups to help to help them get started. Encourage them to review Activity 3, particularly the electromagnet. Ask them to compare the materials they have now with those of Activity 3.

Try to set up the groups so they stay out of each other’s way. Remember that the magnet wire will enable the students to build a system more than 4 meters long, so you will have to plan how to use your space so that systems do not cross over each other.

Electric circuits is a topic notorious for durable, unscientific preconceptions. Even after considerable study, some secondary students cannot draw a simple circuit with a battery and a bulb. You can help your students by discussing their drawing with them before they build the telegraph. Ask them to trace the flow of the current with their fingers. Also, ask them where the current leaves the battery and where it returns.