Explore the fascinating world of magnetism, from permanent magnets to electromagnets, and discover how electric charges create magnetic forces that power our modern world.
Magnetism is a fundamental physical phenomenon produced by the motion of electric charges, resulting in attractive and repulsive forces between objects. It's characterized by the ability of certain materials to attract or repel other materials.
Retain their magnetic properties over time without the need for an external power source.
Bar magnets, Horseshoe magnets, Disc magnets
Act as magnets only while an electric current is flowing through them.
Electromagnets, Solenoids
An iron bar is placed inside a solenoid and connected to a high DC power supply.
Solenoid with Iron Bar
Note: Magnetism is lost when current is turned off (temporary magnet).
A steel or iron bar is stroked with one end of a magnet in a single direction.
Stroking Direction
Result: Creates a permanent magnet through domain alignment.
Easily magnetized and demagnetized, suitable for rapid magnetic field changes.
Difficult to magnetize but retain magnetism for a long time.
Rapid atomic vibration disrupts magnetic domains
Mechanical vibrations disrupt domain alignment
Alternating fields continuously disturb domains
Motors, generators, speakers, microphones
Hard drives, tapes, memory devices
Compasses, GPS systems
MRI machines, magnetic therapy
Interactive quiz on magnetism and electromagnetism
Pieces of soft iron placed across the poles to maintain magnetic domains alignment.
Magnet with Keeper
Benefit: Prevents magnetic domains from repelling each other, maintaining strength.
Magnets stored with opposite poles aligned and soft iron at the ends.
Paired Storage with Iron Pieces
Benefit: Creates closed magnetic loops, reducing field leakage and maintaining strength.
Produced by moving electric charges
Temporary magnets using electricity
Heat, vibration, or AC current
Electronics, storage, navigation