Variation in a compass is caused by（）.

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

Which one of the followings is incorrect about magnetic compass?______.

A.The magentic compass is compulsory on my vessel

B.The magentic compass is prone to error

C.The magentic compass is always placed inside steel constructions

D.The magentic compass needs to be calibrated to compensate for local magnetic distortion

How is variation indicated on a small-scale nautical chart?______.

A.Magnetic compass table

B.Magnetic meridians

C.Isogonic lines

D.Variation is not indicated on small-scale nautical charts

Deviation is the angle between the ______.

A.true meridian and the axis of the compass card

B.true meridian and the magnetic meridian

C.magnetic meridian and the axis of the compass card

D.axis of the compass card and the degaussing meridian

A single vertical magnet placed underneath the compass in the binnacle is used to compensate for ______．

A.The horizontal component of the permanent magnetism

B.Deviation caused by the vessel's inclination from the vertical

C.Induced magnetism in the horizontal soft iron

D.Induced magnetism in the vertical soft iron

Compass error is equal to the ______.

A.deviation minus variation

B.variation plus compass course

C.combined variation and deviation

D.difference between true and magnetic heading

The compass rose on a nautical chart indicates both variation and ______.

A.deviation

B.annual rate of variation change

C.precession

D.compass error

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

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