單項選擇題

What are the only magnetic compass correctors that correct for both permanent and induced effects of magnetism?（）

A.Quadrantal spheres
B.Heeling magnets
C.Athwartships magnets
D.Fore-and-aft magnets

你可能感興趣的試題

Variation is the angular measurement between（）.

A.compass north and magnetic north
B.compass north and true north
C.magnetic meridian and the geographic meridian
D.your vessel's heading and the magnetic meridian

單項選擇題

Variation is a compass error that you（）.

A.can correct by adjusting the compass card
B.can correct by adjusting the compensating magnets
C.can correct by changing the vessel's heading
D.cannot correct