Magnetism Lesson 2 Magnets

A. Induced Magnetism- magnetism that occurs only in the presence of a magnetic field. When the magnetized object is removed from the magnetic field, its pole soon disappear.

B. Atoms themselves have tiny magnetic fields.

C. In a unmagnetized substance, the atomic magnets point in random directions.

D. In substances that are magnetized, the magnetic field are oriented in the same direction.

E. Dropping, striking, or heating can cause domains to go random, demagnetizing.

Some materials can be made into permanent magnets because they retain their magnetism for a long time.

G. Aluminum, nickel, and cobalt are metals that retain their magnetism a long time.

H. Many permanent magnets are made of an alloy of aluminum, nickel, and cobalt called ALNICO

I. Electromagnets- a magnet produced by passing a electric current through a coil of wire wound around a core.

J. Electromagnets are useful because their magnetism can be turned on and off.

K. Electromagnets have fields much stronger than permanent magnets.