1. 4th Grade amazing earth March
Electrical circuits
4th Grade amazing earth
March
Presentation should take about 15 minutes to allow ample time for the activities.   
Ask helpers to:
familiarize themselves with the activity and its goal
set up during the presentation
Thank you for making Amazing Earth possible!

2. What is an electrical circuit?
A pathway made of wires that electricity can flow through.
Needs a power source (e.g., battery) to provide force (voltage) to make the electricity move.
When the electricity gets to a device (e.g., light bulb, computer), it gives it the power it needs to work.
ASK: what is an electrical circuit?
After student responses, advance to bullet points.

3. How does an electrical circuit work?
A circuit needs to be closed to allow the electricity to move.
Wires go from the power source to the device and back again.
If the circuit is broken or open, the electricity can’t move and the device won’t work.
Click Here for Video
Think of a circuit like a circle. The electricity needs a path to travel and return back to the power source. If the circuit (circle) is open, the pathway is broken.
The video is 4 ½ min and gives an overview of how electrical circuits work.
If clicking the link does not work, hold the Function Key and the F8 Key together. Then select Duplicate.

4. Conductors and insulators
Conductors allow electric current to flow freely.
Insulators resist the flow of electric current.
What would be good conductors?
What would be good insulators?
Conductors: metals such as silver, gold, copper, steel, iron; salt water (this has ions in it that conduct electricity which pure water does not); lemon juice
Insulators: rubber, glass, pure water, oil, air
In the pictures, the extension cord has metal wires on the inside but rubber on the outside. Why is this important? The wires conduct electricity but the rubber does not which protects you when you use the cord.
In the pictures, the lemon is used as a power source to conduct electricity and light the light bulb.
Why is it important to have rubber on the outside of the extension cord?

5. Types of circuits Parallel circuits Series circuit Closed circuit
Current divides into two or more paths before recombining
Closed circuit
Current travels in a single pathway through all devices

6. What is engineering design?
Electrical engineers design, develop, test, and supervise the deployment of electrical systems.
The engineering design process is used to plan and implement electrical systems.
Steps to engineering design:
Ask: What is the task?
Imagine: Brainstorm ideas and come up with the best one.
Plan: Draw a diagram. Make a list of materials.
Create: Follow the plan to create the design. Test it out.
Improve: What works? What didn’t work? What can be improved?
Walk the students through the steps of engineering design. They will use these steps to design their circuits and test them out.

7. Today’s activity – Designing circuits
You are a group of electrical engineers who have been asked to create different circuits to power devices. Using the materials you’ve been provided, work together as a team to determine the goal, brainstorm ideas, design, and create your ideas. Discuss improvements that you can make after your initial tests.
Remember the Engineering Design Process
Break into groups of 4-5 back at their tables.
Students can experiment with the Snap Circuits to create different circuits. Encourage them to discuss their plans with their group first and brainstorm ideas together before building.
Updated 2/28/19