Magnetism and electromagnetism

What you'll learn

1. 1

   Imagine a fridge magnet holding a note. It sticks because of an invisible force called magnetism.

2. 2

   What do opposite poles of a magnet do?

3. 3

   Here's a bar magnet. The red end is north, the blue end is south. Opposite ends are next to each other.

4. 4

   Drag the magnet's north pole near the other magnet's south pole. What happens?

5. 5

   Now imagine wrapping a wire around a nail and connecting it to a battery. The wire becomes an electromagnet!

6. 6

   How do you make an electromagnet stronger? Let's think step by step.

7. 7

   What happens if you turn off the battery in an electromagnet?