From: David Gavenda <gavenda@physics.utexas.edu>
Subject: Magnet terminology

I had to clear up the confusing issue of the Earth's North
Pole, so I did some checking of the literature.  Apparently, the end of a
bar magnet labeled "N" was intended to refer to the "North-seeking" pole,
because that end turns toward the "North Geomagnetic Pole".  Later, the
"seeking" was dropped, and it became the "North" pole, in spite of the
fact that it has the opposite property from the North Geomagnetic Pole.
Thus, the North Geomagnetic Pole is a "South-seeking", or, in the
now-standard, confusing terminology, it is a "South" pole.

More modern introductory textbooks avoid all of this confusion by defining
both the direction and strength of a magnetic field from the Lorentz force
law; they tend to ignore the concept of north and south poles completely. 
_____________________________________________________________________________
			Lab 4 - Magnetic Field


	Questions :

	1. In the first 2 parts, you obtained the sketch of magnetic field of
	   a bar magnet, a soft iron bar and then of a soft iron bar with a 
	   magnet placed besides it. Determine which one has stronger magnetic
	   field and explain how to came to this conclusion.
	   ( Hint : Look at the effect of the earth's magnetic field. )


	2. Which of the previous fields is most similar to the field of a
	   rheostat coil and why ?
	   ( Hint : Only half of the rheostat was carrying current. )

	3. How much is the inclination of earth's magnetic field (part 3)
	   and what does it mean ?

	4. Can you expain where the equation  [ B(coil)   = B(earth) tan ø ] comes from ?