The total magnetic effects which cause deviation of a vessel’s compass can be broken down into a series of components which are referred to as（）.

单项选择题The standard magnetic compass heading differs from the true heading by（）.

A.compass error
B.latitude
C.variation
D.deviation

单项选择题The reaction of a gyrocompass to an applied force is known as（）.

A.precession
B.earth rate
C.gyroscopic inertia
D.gravity effect

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 principal purpose of magnetic compass adjustment is to（）.

A.reduce the variation as much as possible
B.reduce the deviation as much as possible
C.reduce the magnetic dip as much as possible
D.allow the compass bowl to swing freely on its gimbals

单项选择题The permanent magnetism of a vessel may change in strength due to（）.

A.a collision with another vessel
B.being moored on a constant heading for a long period of time
C.being struck by lightning
D.All of the above