How is variation indicated on a small-scale nautical chart?（）.

单项选择题If（）is shut down for an extended time optimum position fixing will take up to 2 hours after power is reapplied．

A.radar
B.DF
C.Satellite Navigator
D.Automatic Omega Navigator

单项选择题If a magnetic compass is not affected by any magnetic field other than the Earth’s，which statement is TRUE?（）.

A.Compass error and variation are equal
B.Compass north will be true north
C.Variation will equal deviation
D.There will be no compass error

单项选择题If the compass heading and the magnetic heading are the same then（）.

A.the deviation has been offset by the variation
B.there is something wrong with the compass
C.the compass is being influenced by nearby metals
D.there is no deviation on that heading

单项选择题If the gyrocompass error is east，what describes the error and the correction to be made to gyrocompass headings to obtain true headings?（）.

A.The readings are too low (small numerically) and the amount of the error must be added to the compass to obtain true
B.The readings are too low and the amount of the error must be subtracted from the compass to obtain true
C.The readings are too high (large numerically) and the amount of the error must be added to the compass to obtain true
D.The readings are too high and the amount of the error must be subtracted from the compass to obtain true

单项选择题Magnetic heading differs from compass heading by（）.

A.compass error
B.true heading
C.variation
D.deviation