Magnetism & Magnetic Fields

What is Magnetism & Magnetic Fields?

Have you ever stuck a magnet to your refrigerator or picked up a paper clip with a magnet? Magnets have an invisible pushing and pulling force called magnetism! Every magnet has two ends called poles — a North pole and a South pole. When you bring two opposite poles near each other (North toward South), they snap together like best friends hugging. When you bring two same poles near each other (North toward North or South toward South), they push away like grumpy strangers who do not want to be close. This is called attraction and repulsion. The invisible force around a magnet is called a magnetic field. You cannot see it with your eyes, but you can feel it — and in this simulation you can see the field lines that show where the force reaches. Not everything sticks to a magnet. Only objects made of iron, steel, nickel, or cobalt feel the pull. Gold, plastic, wood, and aluminum do not care about magnets at all. Earth is actually one giant magnet — that is why compass needles always point roughly toward the North Pole! The Earth's magnetic field helps deflect charged particles from the Sun (solar wind); Earth's atmosphere also blocks much of the Sun's harmful radiation.

Parameters explained

Magnet Strength

Strength changes how powerful the magnet is. A low strength makes a small, gentle field. A high strength makes the field lines reach farther and look stronger. Try starting in the middle, then move the slider one step at a time. Watch what changes before you move it again. Ask: do the lines spread out, get brighter, or pull the compass more? This helps students connect a number on a slider with evidence they can see and explain in their own words.

Magnet Position

Position moves the magnet to a new place in the scene. When the magnet moves, the field moves with it because the field belongs to the magnet. Slide it slowly from one side to the other and watch how the field lines shift. Put the magnet near the compass, then farther away. The compass should react more when it is closer to the field. This is a simple way to see that magnetic forces can act across space, even when objects are not touching.

Electric Current

Current controls the electricity in the electromagnet coil. When current is low, the coil makes a weak magnetic field. When current is high, the coil acts more like a strong magnet. Set the Electromagnet coil preset, then move only this slider. Students can see that electricity can make magnetism. A good test is to turn current down, observe, then turn it up and compare the field lines. This keeps the investigation focused on one cause and one visible effect.

Common misconceptions

• MisconceptionAll metals are attracted to magnets.

  CorrectOnly some metals are attracted to magnets. Iron, steel, nickel, and cobalt can stick to a magnet. Many other metals, like aluminum, copper, silver, and gold, usually do not stick. A soda can or a copper penny may look like it should stick because it is metal, but it will not act like iron. Scientists test materials instead of guessing. In class, students can sort objects into 'sticks' and 'does not stick' groups and use their observations as evidence.

• MisconceptionYou can separate a magnet's North pole from its South pole by cutting it in half.

  CorrectIf you cut a magnet in half, you do not get one North-only piece and one South-only piece. You get two smaller magnets. Each smaller magnet still has a North pole and a South pole. Cutting again makes even smaller magnets, but each piece still has two poles. A magnet is like a two-ended team: the ends stay together. This is why students should draw both poles on every magnet piece, even a tiny piece.

• MisconceptionMagnets only work when they are touching something.

  CorrectMagnets can push or pull without touching. The space around a magnet has a magnetic field. That field can reach through air and through thin materials like paper. A paper clip can jump toward a strong magnet before the magnet touches it. The pull gets weaker when the object is farther away, but the field can still be there. This helps students understand a force that acts at a distance.

• MisconceptionA compass needle points north because it wants to point at the map label.

  CorrectA compass needle points because it is a tiny magnet. Earth has a magnetic field, and the needle turns until it lines up with that field. The compass does not read words on a map and it does not know where a person wants to go. It reacts to magnetism. That is why a magnet held too close to a compass can make the needle turn the wrong way for navigation.

How teachers use this lab

1. Begin with the Bar Magnet preset. Ask students to move the Strength slider from low to high, record one observation at each setting, and describe how field-line evidence changes. Connect observations to NGSS 3-PS2-3.
2. Use the Position slider as a proximity investigation. Students predict what will happen when the magnet is moved closer to a compass or test object, then compare the visible result with their prediction. Connect this to NGSS 3-PS2-4.
3. Switch to the Electromagnet coil preset. Keep Position and Strength steady while students change only Current. Have them explain how electricity can produce a magnetic effect using claim-evidence-reasoning language.
4. Use the Compass Navigation preset for a navigation mini-lesson. Students observe how the compass needle lines up with the field, then discuss why real compasses must be kept away from strong classroom magnets.
5. Run a materials-sorting station before the digital activity. Students test paper clips, foil, coins, plastic, and steel objects, then use the simulation to explain why only some materials respond strongly to magnetic fields.