單項選擇題

The greatest directive force is exerted on the magnetic compass when the（）.

A.needles are nearly in line with the meridian
B.vessel is near the magnetic poles
C.variation is near zero
D.vessel is near the magnetic equator

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單項選擇題

The Flinders bar on a magnetic compass compensates for the（）.

A.induced magnetism in vertical soft iron
B.induced magnetism in horizontal soft iron
C.permanent magnetism in ship's steel
D.vessel's inclination from the vertical

單項選擇題

The error in a magnetic compass caused by the vessel’s magnetism is called（）.

A.variation
B.deviation
C.compass error
D.bearing error