单项选择题
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
Deviation in a compass is caused by the（）.A.vessels geo...
单项选择题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
Compass error is equal to the（）.A.deviation minus varia...
单项选择题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
Compass deviation is caused by（）.A.magnetism from the e...
单项选择题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
