Ch 7. Magnetism: Key Concepts and Classifications for Physics

1. Q: The ability of certain materials to attract iron, cobalt, or nickel is known as what?

Magnetism

2. Q: The three classifications of magnets are.

natural (like earth and lodestone), artificial permanent, Electromagnets

Electromagnet

temporary magnets produced by electric currents

natural magnet

loadstone or earth

Artificial permanent magnet

Artificially magnetized bar or horseshoe shaped piece of hard steel

3. Q: Like magnetic poles _____, while unlike magnetic poles _____.

Repel; attract

4. Q: Magnetism can be attributed to the property of what?

Electron spin

5. Q: If the electron spins of an atom's electrons are aligned oppositely, their magnetic fields do what?

Cancel

6. Q: Atoms of magnetic materials have two more electrons spinning in one direction than the opposite direction, creating what

A pole (or magnetic moment)

7. Q: Billions of dipoles occur in what, in which all dipoles are aligned in the same direction?

Domains

8. Q: In the non-magnetized state of iron, the domains are in what arrangement?

Random state of disorder

9. Q: In the magnetized state of iron, the domains are aligned how?

All with north poles pointing in one direction and south poles in the opposite direction

10. Q: In nonmagnetic elements, just as many electrons spin in one direction as the other. True or false?

True

11. Q: Surrounding a magnet there is a zone of influence called what?

Magnetic field

12. Q: The closer the lines of force are, the ____ the magnetic field.

Stronger

13. Q: Lines of force always flow from the ____ pole to the ____ pole outside the magnet.

North; South

14. Q: Lines of force always flow from the ____ pole to the ____ pole inside the magnet.

South; North

15. Q: Lines of force repel when they are in the same direction and do what when in opposite directions?

Attract

16. Q: Iron becomes temporarily magnetized while lying in a magnetic field due to what?

Magnetic induction

17. Q: When a piece of nonmagnetized iron is brought near one pole of a magnet, the end of the iron nearest the pole assumes what polarity?

Opposite

18. Q: When iron is removed from the magnetic field, the magnetic domains do what?

Scramble

19. Q: The ease with which a material can be magnetized is known as what?

Permeability

20. Q: The ability of a magnet to resist demagnetization is known as what

Retentivity

21. Q: A metal with high permeability will have ____ retentivity

Low

22. Q: A metal with low permeability will have ____ retentivity.

High

23. Q: ____ materials are strongly attracted by a magnetic field

Ferromagnetic : materials like nickel, cobalt, and iron

24. Q: ____ materials are weakly attracted by a magnet.

Paramagnetic : materials like platinum

25. Q: ____ materials are not attracted by a magnet

Non-magnetic :materials like wood, plastic, and glass

26. Q: ____ materials are repelled by a magnet.

Diamagnetic - materials like beryllium and bismuth