Here you are a presentation about de contents of this unit to explain de main aspects of structures.

You can watch the video and download the file.

Here you are the unit about structures

HOW ELECTRICITY WORKS

https://youtu.be/mc979OhitAg

Click on the following video to get introduced on the topic about electricity.

Pay special attention to:

Why do some materials conduct electricity?
What is electric current?
What is a circuit?
Which are the basic electrical magnitudes?