单项选择题
A.vessel's geographic position B.vessel's heading C.earth's magnetic field D.influence of the magnetic materials of the vessel
Deviation is the angle between the（）.A.true meridian an...
单项选择题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
Error may be introduced into a magnetic compass by（）.A....
单项选择题Error may be introduced into a magnetic compass by（）.
A.making a structural change to the vessel B.a short circuit near the compass C.belt buckles D.All of the above
Gyrocompass repeaters reproduce the indications of the ...
单项选择题Gyrocompass repeaters reproduce the indications of the master gyrocompass. They are（）.
A.accurate only in the Polar regions B.accurate electronic servomechanisms C.hand operated D.accurate only if the vessel is underway
