Chapter 10 - Terrestrial Magnetism Flashcards
What is magnetism?
A property that magnetised metallic elements and alloys can have naturally or induced.
What are the characteristics of a magnet?
Attracting other metals
North Seeking
Where is the magnetism strongest?
At the poles
By convention what are the two poles of a magnet described as?
RED and BLUE
By convention the north seeking pole is RED
What MUST a magnet have?
A north and a south pole
If a magnet is cut, what happens?
If a magnet is cut, new poles are made available
What is the inverse square law?
magnetic forces behave according to an inverse square law, in other words, the force exerted between two magnetic poles is inversely proportional to the square of the distance between them, or:
F = Force Between the Poles.
D = Distance Between the Poles
F α 1/d^2
repulsive force between two like poles also depends on the strength of these poles. For instance, if the strength of one of the poles is doubled, then the repulsive force is doubled.
The poles of the hypothetical earth magnet do not lie on the earths spin axis and are not …..
antipodal
What do we call the movement of the magnetic North Pole?
Secular Change
What are isogonal lines?
Lines of equal magnetic variation
What are agonic lines?
Lines of zero magnetic variation
What is the dip angle?
one end of a freely suspended magnet will dip below the horizontal plane and point to the nearer pole
What do dip error cause?
Turning errors
Acceleration errors
In what direction do dip errors increase?
From the equator to the N/S Pole
What 2 forces make up the magnetic force?
Horizontal (H) - The directive force
Vertical (Z)
