What Is an Electromagnet and How Does It Work?

What Is an Electromagnet

What Is an Electromagnet and How Does It Work?

Key Points

  • An electromagnet produces a magnetic field when an electrical current flows through conductive wires wrapped around a metal core.
  • A permanent magnet always has a magnetic field, while an electromagnet only has a magnetic field when an electrical current is passing through it.
  • Electromagnets are widely used in everyday electronics due to their ability to control the magnetic field and adjust its intensity.
  • Electromagnets can be found in headphones, speakers, hard drives, door locks, electric motors, heavy lifting equipment, MRI machines, and scanning electron microscopes.

Electromagnet: Exact Definition

An electromagnet produces a magnetic field when an electrical current flows through conductive wires (like copper) that are wrapped around a core (a metal rod) that can accept a magnetic field.

While a “permanent” magnet has a magnetic field encompassing the magnet at all times, an electromagnet has a magnetic field that’s present only when an electrical current passes through it. You can turn an electromagnet on or off.

What Is a Magnet: Complete Explanation

With this in mind, a magnet, also known as a permanent magnet, always creates a magnetic field. For example, a permanent magnet is created from ferromagnetic materials (iron, cobalt, or nickel).

The atomic structure of atoms in a ferromagnetic material is lined “in” and “aimed” in the same direction. Additionally, the orientation of ferromagnetic materials allows them to be magnetized.

Atoms grouped will form their own magnetic domain, a positive or negative magnetic domain. However, the magnetic domain is random. In the image below on the left (“unmagnetized material”), you can see the randomized direction of the domains.

what is an electromagnet
A domain is a region inside of a material where groups of magnetic moments align in the same direction.


Unmagnetized materials can be magnetized. The most common form of creating magnets is the process of powder metallurgy (PM).

  • Elements are ground into fine powder.
  • The powder is heated and compressed inside a form. The form comes in any desired shape. A “U” shape, a flat “box” shape — you name it.
  • A magnetic field (aligning field) is applied during the heating and compaction phase — the aligning field “readies” the magnet to accept a magnetic charge.
  • The process is completed when the newly formed magnet (lacking any magnetic properties) is subjected to magnetic forces. The newly formed “almost magnet” is placed close to a much larger magnet. The electrons located in the “almost magnets” atoms will orient themselves to match their spins to the magnetic field of the larger magnet.
  • The “almost magnet” is now a permanent magnet. A reasonable expectation of the permanent magnet is that it will lose approximately one percent of its magnetic field each year. If you take care of your magnet, it will last a long time. We’ll talk about caring for your magnets a bit later.

What Is an Electromagnet: Complete Explanation

An electromagnet is a magnet that produces an invisible magnetic field of varying strength based on the electricity flowing through it. While a permanent magnet always has a magnetic field, an electromagnet only has a magnetic field when an electrical current is passing through it.

A permanent magnet has a constant magnetic field, but electromagnets cease having a magnetic field when the electrical current stops. The ability to control the magnetic field, and increase or decrease its intensity, has made the electromagnet incredibly popular and widely utilized in common everyday electronics.

How Does an Electromagnet Work?

An electromagnet is a piece of metal (think of it as a core) that’s wrapped (around and around) with a long strand of conductive wire (generally copper). When you introduce an electrical current (turning on a switch), current flows throughout the wire.

The current flowing through the coiled conductive wire creates a magnetic field. The magnetic field magnetizes the metal core. The metal core now behaves like a permanent magnet. When the electricity turns off, the core is no longer magnetic.

what is an electromagnet
Electromagnets usually consist of wire wound into a coil.


In the image above, the battery represents the electrical current. The current flows into the coil of wires at one end, the south, and exits the battery at the other end of the coil, the north. The north and south ends of the diagram also represent the opposite forces of the magnetic field, the North and South.

Electromagnets are also known as “temporary magnets.” Temporary magnets lose their magnetic charge when you remove the electrical current.

We’d be completely remiss in our discussion of electromagnets not to tell you how you build your own electromagnet! Let’s build an electromagnet; it’s easier than you might think.

How Do You Create an Electromagnet?

While it sounds daunting, it’s quite simple to create an electromagnet.

  • Step 1: Find some copper wire; we suggest around 12 AWG.
  • Step 2: Locate an iron nail, maybe three or four inches. A longer nail is better than a shorter nail!
  • Step 3: Wrap the copper wire around the nail. Don’t overlap the wire on top of itself.
  • Step 4: Strip the ends of the copper wire and remove the insulation. About an inch of bare wire on each end of the coil is perfect.
what is an electromagnet
The electric field in the wire coil creates a magnetic field around the nail.


  • Step 5: Attach one of the copper wires to the positive end of the battery. Attach the other end of the copper wire to the negative end of the battery.
    • In the diagram above, the construction shows alligator clips. This is a bit of overkill. You can use electrical tape or your fingers to make a connection. (This isn’t rocket science!)
  • Step 6: The iron nail becomes magnetized with the current flowing from your battery through the copper wires. Try it out with some paperclips or staples.
  • Step 7: The wire will heat up as the current passes through it. Mind your fingers, and don’t try to brand your pet.

There you go! With minimal tools and hardware, you, too, can create an electromagnet. It’s hard to imagine, but there was a time not so long ago when electromagnets hadn’t been invented. Who invented them?

Who Created the Electromagnet?

In 1825, British electrical engineer William Sturgeon invented the electromagnet. Sturgeon built the electromagnet from a horseshoe-shaped piece of iron, wrapping the iron with wire.

When current passed through the wire, the horseshoe became magnetized. Sturgeon proved that the magnetic field increased in strength when higher levels of current passed through the wire coils. He lifted a nine-pound weight through a seven-ounce electromagnet core wrapped with wire.

In 1830, American inventor Joseph Henry demonstrated the use of the electromagnet by sending an electrical current through a wire stretched out for one mile, activating another electromagnet on the other end of the wire.

The electromagnet on the far end of the wire (one mile away) started a bell to ring. Thus began the age of the telegraph.

What Are the Applications of Electromagnets?

Electromagnetic technology has advanced tremendously since its invention in 1825, yet its principles remain the same today.  Electromagnets are (literally) everywhere around us.

We’ll bet that by the time you’ve finished reading this article, you’ll be able to locate ten or fifteen electromagnetic applications within ten feet of where you’re sitting right now!

Examples of Electromagnets In the Real World

Today, you’ll have a hard time not finding electromagnets in use all around you. Let’s start assembling a list!

Headphones and Speakers

Did you know that headphones and speakers have electromagnets in them? For example, how many headphones and speakers (don’t forget your cell phone!) are within your current line of sight? (We count twelve from our desk!)

Hard Drives

A hard disk drive (HDD) contains a read-and-write head that magnetizes portions of the disk (called sectors). Each section has a one or a zero value assigned.

In addition, the hard disk has rotating platters (they look like CDs) that spin at high speed. As a result, the same read-and-write disk reads the magnetized sectors of the disk.

Door Locks

You don’t need to look further than your front door to find an electromagnetic lock. Rapidly gaining popularity, electromagnetic door locks use electrical current to activate a door lock.

An electrical current is applied to the door lock, and the lock is activated (locked). No sooner than the electrical current is removed from the door lock, the lock is deactivated (unlocked).

Electric Motors

Looking around your home, you’ll be hard-pressed not to find a vacuum, refrigerator, blender, washing machine, hair dryer, dishwasher, or microwave. But did you realize that each application also uses an electromagnet?

Heavy Lifting

Automotive junkyards use electromagnets to lift cars and move them around the scrap yard. Electromagnets are also common items on construction sites, used to pick up and transport steel plates or scrap metals.

Magnetic Resonance Imaging

Electromagnets are common pieces in magnetic resonance imaging (MRI). Patients lie within a strong magnetic field for testing. First, the magnetic field stimulates the patient’s protons. Then, the protons start to spin out of whack (equilibrium).

Accordingly, the protons realign when you deactivate the magnetic field. The MRI device allows physicians to differentiate between different types of soft tissue. The MRI will help identify aneurysms, strokes, blood clots, and inflammation (to name a few)!

Scanning Electron Microscopes

Electromagnets play a key role in scanning electron microscopes. As a result, scanning electron microscopes (SEMs) collect electrons (instead of light) to create a magnified image. Then, a series of electromagnets come together as a “lens” to focus the electrons on a collector.

what is an electromagnet
A SEM produces images by scanning the surface of a sample with a focused beam of electrons.


Find scanning electron microscopes are used daily in science, medicine, manufacturing, and education. In the image above, an SEM collected an astounding close-up image of a fly’s eye. Electromagnets helped to focus the image.

Summary Table

Electromagnet ComponentsDescription
DefinitionAn electromagnet produces a magnetic field when an electrical current flows through conductive wires wrapped around a core that can accept a magnetic field.
How it WorksAn electromagnet is a piece of metal wrapped with a conductive wire. When an electrical current is introduced, it flows through the wire, creating a magnetic field that magnetizes the metal core.
CreationAn electromagnet can be created with minimal tools and hardware. It requires a metal core, conductive wire, and a source of electrical current.
InventorBritish electrical engineer William Sturgeon invented the electromagnet in 1825.
ApplicationsElectromagnets are used in headphones, speakers, hard drives, door locks, electric motors, heavy lifting equipment, magnetic resonance imaging, and scanning electron microscopes.

Frequently Asked Questions

How does a simple electromagnet work?

A magnetic field is generated when an electrical current is passed through a coiled wire (such as copper) that’s wrapped around a Ferromagnetic (magnetic) core.

What is a good example of an electromagnet?

Hard Disk Drives, dishwashers, headphones, speakers, microwaves, motors, dishwashers, doorbells (old school with a ringer, not a “Ring” device), MRIs, and door locks.

Is an electromagnet a magnet?

Yes. An electromagnet functions as a magnet when (and only when) an electrical current is applied. When the electrical current is removed from the electrical magnet, a magnetic field is no longer generated.

What is the difference between a magnet and an electromagnet?

A magnet, otherwise known as a permanent magnet, always has an active magnetic field. A permanent magnet is magnetized. An electromagnet is only magnetized and generates a magnetic field when an electrical current flows through them. No electricity equals no electromagnet.

What three things do you need to make an electromagnet?

A battery, copper wiring, and a iron nail are all you need to make your own electromagnet.

Are electromagnets stronger than magnets?

Yes, but it depends too. An electromagnet’s strength can be increased or decreased by increasing or decreasing the amount of the electrical current flowing through the electromagnet’s wire coils. To increase the power of the electromagnet, the electrical current is increased. To decrease the strength of the electromagnet, the electrical current is decreased.

So, overall, yes, electromagnets are stronger than magnets because the magnetic field can be increased by applying more electrical current.

Do magnets wear out?

Provided you treat your magnet nicely, it will outlast you! Here are four items that will keep your magnet happy and healthy:

1: Keep your permanent magnet away from high (176°F) heat.
2: Don’t throw your magnet at a brick wall. The sudden impact on the brick wall may cause fractures of the magnet material.
3: Don’t weld next to your magnet.
4: Exterior fissures may allow moisture ingress. A nice sealant is your friend if you notice cracks.

Why can't we use magnets for energy?

Magnets have a magnetic field but don’t generate energy. Magnets are used in about 99 percent of the energy conversion from one form to another; wind, nuclear, fossil fuels, and hydroelectric all use magnetic fields in the conversion process.

Can electromagnetic fields cause health problems?

Absolutely. There are well-established criteria for what is considered safe and unsafe for workers that are in close proximity to higher levels of electromagnetic fields.

What needs to be better established is lower threshold limitations for electromagnetic fields. As the number of electronic devices in our homes has increased (and continues to do so,) the amount of low-level electromagnetic fields increases. We absorb the electromagnetic fields and run the charge to ground. What’s unknown, lacking scientific evidence, is a link between health issues and low levels of electromagnetic fields.

Some folks have complained about depression, nausea, loss of libido, fatigue, and headaches that they attribute to electromagnetic fields at home. To date, there are no scientific studies to support these claims.

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