Physics of electromagnetism

Welcome! I'm really excited to dive into electromagnetism with you. Before we sketch out our learning path and get into the physics, I'd love to know a bit more about you so I can tailor everything perfectly to your style.

For my 7th grade students

It is wonderful that you are bringing this to 7th graders! Knowing where they are starting from helps me frame our journey perfectly.

To help me pitch this at the right level for your students, have they already covered basic electricity (like or static electricity) or basic magnetism (like how work) in their science classes yet?

They have covered both electricity and magnetism.

That is absolutely perfect! Since they already know about closed loops and magnet poles, we can skip the basics and show them how these two ideas are actually two sides of the exact same coin.

Your path

Electric and Magnetic Fields

Electromagnetic Applications

The Grand Connection

For centuries, scientists treated electricity and magnetism as completely separate topics. It was not until noticed a compass needle twitching near a live wire in 1820 that humanity realized they are fundamentally linked. At its core, electromagnetism is the physical interaction between electrical charges and magnetic fields. For your 7th graders, the magic hook is this: moving electric charges always create an invisible magnetic field around them. When a circuit is off, the electrons sit relatively still, and there is no magnetic field. But the moment you flip that switch and current begins to flow, an invisible magnetic tunnel forms around the wire. It is like electricity is a runner, and their movement automatically stirs up a magnetic wind.

Three-dimensional perspective projection of circular magnetic field lines wrapping around a straight copper wire carrying an electric current.

I'm generating a quick visual placeholder above so you can see how to sketch this on the blackboard for them.

Next, we should look at how we can bundle this concept into a physical project your students can hold in their hands.

Continue to building a simple electromagnet

Building a simple electromagnet is one of the most satisfying hands-on science activities you can do with middle schoolers because they get to construct a functional machine from scratch using just three basic ingredients.

The Recipe for a Magnet

To guide your 7th graders through this, each student or group will need:

One large steel or iron nail (about 3 inches long)
A length of thin,
A fresh AA or D-cell battery
A handful of metal paperclips to test their creation.

To build it, students tightly wrap the copper wire around the nail, leaving about 8 inches of loose wire hanging off each end. The tighter and neater the coils, the stronger the magnetic force will be. Once wrapped, you scrape a tiny bit of the protective insulation off the very tips of the wire ends so they can make clean electrical contact with the battery terminals.

An electromagnet in its active state with a wire coiled around a steel nail connected to a battery.

A Quick Safety Note

Before your students connect their wires, there is one key safety rule to emphasize: it will get warm.

Because the wire is wrapped directly between the positive and negative ends of the battery, we are essentially creating a . Without a lightbulb or resistor to slow down the flow of electricity, the current will flow rapidly, which causes the wire and the battery to heat up.

Teach your students to use a 'tap and test' method rather than leaving the wires permanently taped to the battery. They should hold the wire ends against the battery terminals only long enough to pick up some paperclips, and then disconnect them.