A.They are not subject to permanent magnetism; no check is necessary
B.Semiannually
C.Annually
D.Every five years
您可能感興趣的試卷
你可能感興趣的試題
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
A.GPS
B.GMDSS
C.AIS
D.Navtex
A.Black
B.Blue
C.Red
D.White
A.flux
B.poles
C.magnets
D.azimuth
A.If the blue ends of the magnets are aft，and the fore-and-aft tray is at the top，you should add some magnets
B.If the blue ends of the magnets are aft you should lower the fore-and-aft tray
C.If the blue ends of the magnets are aft，and the fore-and-aft tray is at the top，you should reverse the magnets
D.If the blue ends of the magnets are forward，and the fore-and-aft tray is at the bottom，you should add some magnets
最新試題
A vessel is heading magnetic east and its magnetic compass indicates a heading of 086°.Which action should be taken to remove this error during compass adjustment（）.
What is the name of the movable，radial guide line used to measure direction on a radar?（）
What is the basic principle of the magnetic compass（）.
The magnetism in the various structures of a ship changing as a result of cruising，vibration，or aging is termed（）.
The most accurate method of determining gyrocompass error while underway is by（）.
What is used to correct for both induced and permanent magnetism，and consequently must be readjusted with radical changes in latitude（）.
Which magnetic compass corrector（s）can be set while the vessel is on a heading of magnetic north or magnetic south（）.
When adjusting a magnetic compass using the fore-and-aft permanent magnets，you should（）.
Any piece of metal on becoming magnetized will develop regions of concentrated magnetism called（）.
The variation for most given areas undergoes（）change，the amount of which is also noted on charts.