航海英语磁罗经与陀螺罗经的使用章节练习(2017.10.30)

单项选择题
By convention，the north seeking ends of a compass’ magnets are colored（）.
A.Black
B.Blue
C.Red
D.White
单项选择题
A ship under construction or major repair will acquire permanent magnetism due to（）while sitting stationary in the earth’s magnetic field.
A.hammering and jarring
B.vibration and pounding
C.varying magnetic fields
D.stable or permanent magnetism of the ship
单项选择题
The horizontal angle between the magnetic meridian and the north-south line of the magnetic compass is（）.
A.deviation
B.variation
C.compass error
D.dip
单项选择题
The quadrantal spheres are used to（）.
A.remove deviation on the intercardinal headings
B.remove deviation on the cardinal compass headings
C.remove heeling error
D.compensate for induced magnetism in vertical soft iron
单项选择题
The MOST important feature of the material used for making the binnacle of a standard magnetic compass is that it is（）.
A.nonmagnetic
B.weatherproof
C.corrosion resistant
D.capable of being permanently affixed to the vessel
单项选择题
What is used to correct for both induced and permanent magnetism，and consequently must be readjusted with radical changes in latitude（）.
A.Flinders bar
B.Soft iron spheres
C.Fore-and-aft permanent magnets in their trays
D.Heeling magnet
单项选择题
The line which connects the points of zero magnetic dip is（）.
A.An agonic line
B.The magnetic equator
C.A magnetic meridian
D.All of the above
单项选择题
When relieving the helm，the new helmsman should know the（）.
A.Course per magnetic steering compass
B.Gyro error
C.Variation
D.Maximum rudder angle previously used
单项选择题
The lubber’s line of a magnetic compass（）.
A.always shows true north direction
B.indicates the vessel's heading
C.is always parallel to the vessel's transom
D.is located on the compass card
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