单选题The lubber’s line on a magnetic compass indicates（）.A compass northB the direction of the vessel's headC magnetic northD a relative bearing taken with an azimuth circle

A vessel is heading magnetic north and its magnetic compass indicates a heading of 003°. What action should be taken to remove this error during compass adjustment?

A.Move the quadrantal spheres closer to the compass

B.Raise the heeling magnet if the red end is up

C.Remove some of the Flinders bar

D.Raise or lower the athwartship magnets

Which magnetic compass corrector（s）CANNOT be set on a heading of magnetic east or magnetic west ________．

A.Heeling magnet

B.Flinders bar

C.Fore-and-aft magnets

D.All of the above can be set on magnetic east or magnetic west headings

The agonic line on an isomagnetic chart indicates the ______.

A.magnetic equator

B.magnetic longitude reference line

C.points where there is no variation

D.points where there is no annual change in variation

Magnetic dip is a measurement of the angle between the ______.

A.geographic pole and the magnetic pole

B.lubber’s line and true north

C.horizontal and the magnetic line of force

D.compass heading and the magnetic heading

Deviation in a compass is caused by the ______.

A.vessel’s geographic position

B.vessel’s heading

C.earth’s magnetic field

D.influence of the magnetic materials of the vessel

Your vessel is proceeding down a channel，and you see a pair of range lights that are in line dead ahead．The chart indicates that the direction of this pair of lights is 229°T，and variation is 6°W．If the heading of your vessel at the time of the sighting is 232°per standard magnetic compass，what is the correct deviation ________．

A.3°E

B.9°E

C.3°W

D.9°W

Compass deviation is caused by ______.

A.magnetism from the earth’s magnetic field

B.misalignment of the compass

C.magnetism within the vessel

D.a dirty compass housing

On a nautical chart，the inner ring of a compass rose indicates ______.

A.true directions

B.compass error

C.deviation

D.magnetic directions

If a magnetic compass is not affected by any magnetic field other than the Earth’s which statement is TRUE?______.

A.Compass error and variation are equal

B.Compass north will be true north

C.Variation will equal deviation

D.There will be no compass error