单项选择题
A.damping error B.ballistic deflection C.quadrantal error D.speed error
The greatest directive force is exerted on the magnetic...
单项选择题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
The Flinders bar on a magnetic compass compensates for ...
单项选择题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
The error in a magnetic compass caused by the vessel’s ...
单项选择题The error in a magnetic compass caused by the vessel’s magnetism is called（）.
A.variation B.deviation C.compass error D.bearing error
