单项选择题
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
The directive force of a gyrocompass（）.A.increases with...
单项选择题The directive force of a gyrocompass（）.
A.increases with latitude，being maximum at the geographic poles B.decreases with latitude，being maximum at the geographic equator C.is greatest when a vessel is near the Earth's magnetic equator D.remains the same at all latitudes
