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40 Cards in this Set
- Front
- Back
- 3rd side (hint)
The property of certain metals to attract or repel items of like material or certain other metals also can e an effect of electrical currents |
magnetism |
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Magnetism that is only present when the material is under the influence of an external field |
Induced Magnetism |
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Iron or steel which is easily magnetized by induction, but loses it magnetism when a magnetic field is removed |
Soft Iron |
If your soft you get no attraction |
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The ______________the iron, the longer it will maintain its magnetic property's once removed from a magnetic influence. |
harder |
Hard people get attraction |
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is the magnetism remaining after the magnetizing force is removed |
residual magnetism |
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Is the magnetism that remains for long periods of time without any appreciable reduction, unless is subjected to a demagnetizing force |
Permanent magnetism |
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Do the geographic poles match the magnetic poles? |
NO |
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the magnetic lines of force that connect the magnetic poles. These lines are irregular shaped to non-uniform distribution of magnetic in the earth surface. |
Magnetic Meridians |
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Located midway between the poles |
The magnetic Equator |
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The difference between magnetic meridians and true meridians |
Magnetic Variation |
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Daily changes which are caused by the movement of the magnetic poles in an orbit having a diameter of about 50 miles |
diurnal change. |
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the yearly permanent changes in the earths magnetic field. |
Annual Change |
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Changes in magnetism over a period of years |
secular changes` |
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lines on the magnetic chart that connect points of equal variation or magnetic and having equal angles |
Isogonic Lines |
Means equal |
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Lines joining points of zero magnetic variation, a special case of an isogonic lines |
Agonic lines |
Destroyer of magnetism |
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Angle between the magnetic meridian and the axis of the compass card |
magnetic Deviation |
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Caused by the disturbing magnetic influences in the immediate vicinity of the magnetic compass |
Deviation |
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Ships are built with a ______________________heading |
North and South |
Monitor vs Virginia |
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Ships are refitted on a ______________________heading ofsetting the deviation acquired during construction |
east and west |
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Neutralizing of the strength of the magnetic field of a vessel |
Degaussing |
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Ships take on permanent magnetic properties referred to it's _______________. |
Magnetic Signature. |
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Is placed on the weather deck in a location where magnetic influences are the least. |
Standard Compass (PSC) |
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is placed center lined and just forward of the steering wheel. |
Steering compass |
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Bowl shaped container of non-magnetic materail which serves to contain the elements, a reference mark, and the fluid |
Compass Bowl |
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The reference mark on the inside of the compass bowl used to read the direction of the ships heading |
Lubber Line |
I love not crashing into **** |
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-Aluminum disk graduated in degrees Showing cardinal and inter cardinal points |
Compass Card |
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Four bundles of magnetic steel wire or bar magnets. These are attached to the compass card to supply directive force |
MAGNETS |
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What fluid is used in a compass? |
Varsol or alcohol |
Keeps everything floating |
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Aluminum air-filled chamber in the center of the compass card |
Float |
Something to hold on to |
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Designed to compensate for temperature changes attached to the bottom of the compass bowl |
Expansion bellows |
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Permits the compass bowl to remain horizontal regardless of the vessels movement |
Gimbles |
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A stand made of non-magnetic material in which the compass is mounted Inside are trays or holders for the fore and aft magnets used for adjusting the compass |
Binnacle |
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Soft Iron on both sides of the binnacle. -Used to offset induced magnetism caused by the ships' structure, also used in adjusting the compass |
Quadrantal Spheres |
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Soft iron having no permanent magnetism located in a side mounted tube on the compass binnacle vertically |
Flinders Bar |
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Located in a vertical tube directly below the center of the compass Magnets used to steady the compass card "swing" or oscillations |
Heeling Magnets |
When you want a 🐶 to ⛔ |
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Advantages of a gyro Compass |
-Seeks true meridian -Can be used near magnetic poles -Not affected by surrounding magnetic materials. -Errors are the same on all headings |
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Disadvantages of a gyrocompass |
requires a constant power source requires intelligent care and attention accuracy decreases above 75 degrees may have to resettle if the operation is interrupted |
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The gyrocompass has how many degrees of freedom |
3 |
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once the gyroscope starts to spin, it will resist change in the orientation of the spin axis |
Gyroscopic Inertia |
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If a torque or twistin force is applied to the spin axis, the axis will not turn in the direction in the direction of the torque, but will instead move in a direction perpendicular to it |
Precession |
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