Prin. of Tech

Magnetism Web quest

(All answers should be hand written on a separate piece of paper.)

 

General questions

The following webpage (and the pages that follow by hitting the “next” button) contain good information about the source and properties of magnetism

http://www.ndt-ed.org/EducationResources/CommunityCollege/MagParticle/Physics/Magnetism.htm

1) What causes magnetism inside the atom?

2) Why are unpaired electrons more significant than paired electrons in terms of magnetic properties?

3) What causes a material to be classified as “ferromagnetic”? Name some examples of ferromagnetic materials.

4) What is a magnetic domain? Sketch two images of a material that has magnetic domains, one that is magnetized and one that is un-magnetized.

5) Sketch a bar magnet. Label the poles of the magnet with an “N” and an “S”. Draw magnetic field lines (with direction) both inside and outside of the magnet.

 

Field Reversals

Read this 2-page article about geomagnetism from National Geographic

http://news.nationalgeographic.com/news/2004/09/0909_040909_earthmagfield.html

  1. How long have scientists been recording the strength of the Earth’s magnetic field?
  2. What is happening to the Earth’s field right now?

3) How does the magnetic field act like a shield?

4) What animals use the Earth’s magnetic field for navigation?

5)  is the average time between  field reversals?

6) When is the last time the Earth’s field reversed?

7) What is the “geodynamo”, and what is believed to be the cause of it?


Magnetic Declination

Answer the next several questions using the following webpage as well the link that reads, “What is Magnetic Declination?”

http://www.magnetic-declination.com/

1) What is magnetic declination and what causes it?

2) What do the terms “geographic north” and “magnetic north” mean?

3) What is the magnetic declination in Chicago (include + or -)?

4) If you wanted to walk in the direction of true north in Chicago, would you want to walk to the left or right of where a compass needle points?

5) Where, geographically, is magnetic declination the worst?