航海英语航海仪器单项选择题每日一练(2017.10.03)

单项选择题
The permanent magnetism of a vessel may change in polarity due to（）.
A.being moored for a long time on one heading
B.being struck by lighting
C.steaming from the north magnetic hemisphere to the south magnetic hemisphere
D.loading a homogenous magnetic cargo such as steel plate，iron bars，etc
单项选择题
The heading of a vessel is indicated by what part of the compass? （）
A.Card
B.Needle
C.Lubber's line
D.Gimbals
单项选择题
When adjusting a magnetic compass using the fore-and-aft permanent magnets，you should（）.
A.use the magnets one at a time，putting one in one side and then one on the opposite side，one step higher
B.use the magnets in pairs，starting at the top，with trays at the highest point of travel
C.use the magnets in pairs，from the bottom up，with the trays at the lowest point of travel
D.fill all the trays with magnets，then remove them one-by-one until the deviation is removed
单项选择题
While in drydock your vessel will be belt-gauged.This process involves（）.
A.measuring the thickness of the tail shaft liner
B.taking the vessel's offsets to check for hull deformation
C.testing and examining the anchor cables for defective links
D.drilling or sonic-testing the hull to determine the plate thickness
单项选择题
You are using a radar in which your own ship is shown at the center，and the heading flash always points to 0°. If bearings are measured in relation to the flash，what type of bearings are produced?（）.
A.Relative
B.TRUE
C.Compass
D.Magnetic