Introduction to Magnets

Introduction to Magnetism

Where does magnetism come from?

• Moving charge or currents can create a magnetic field

• A magnetic field is also found in permanent magnetic materials like a piece of iron

Magnets always have a north and a south pole

Like poles (north-north, south-south) repel and unalike poles attract (north-south)

Some questions about magnetism...

• Can a magnet ever have just a north pole or just a south pole? Why not?

• What does the magnetic field surrounding a bar magnet look like?

• How are the geographic poles of the Earth related to its magnetic poles?

• How does magnetism arise at the microscopic level?

• Is the direction of the magnetic force in the same direction as the magnetic field?

• What are some technological applications of magnetism?

• What happens when two wires carrying current are placed side-by-side?

Where do we see magnetism in nature?

Animals Use Magnetism to Navigate

Animals can use magnetism to perceive direction, altitude, or location

What are some technological applications of magnetism?

Magnetic Resonance Imaging (MRI)

You are literally placed in the middle of a large magnet. Through the variation of the magnetic field in different parts of the body, powerful computers can construct very detailed images of the body's internal structure.

Motors

Motors use the interaction of electricity magnetism and magnetism to generate a force.

Multiple Select

What two technological applications of magnetism did I mention?

• MRI

• Motors

• Lasers

• Lightbulbs

Open Ended

Give an example of magnetism in nature.

Open Ended

What's one question you have about magnetism?