音域（Compass）

The compass rose on a nautical chart indicates both variation and ______.

A.deviation

B.annual rate of variation change

C.precession

D.compass error

Compass deviation is caused by ______.

A.magnetism from the earth’s magnetic field

B.misalignment of the compass

C.magnetism within the vessel

D.a dirty compass housing

The compass error of a magnetic compass that has no deviation is ______.

A.zero

B.equal to variation

C.eliminated by adjusting the compass

D.constant at any geographical location

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

Deviation is the angle between the ______.

A.true meridian and the axis of the compass card

B.true meridian and the magnetic meridian

C.magnetic meridian and the axis of the compass card

D.axis of the compass card and the degaussing meridian

When an azimuth of the Sun has been taken and the deviation of the standard magnetic compass computed，the watch officer should record the results ______.

A.in the vessel's Official Logbook

B.on the compass deviation card

C.in the compass deviation log

D.on a Napier diagram

Compass error is equal to the ______.

A.deviation minus variation

B.variation plus compass course

C.combined variation and deviation

D.difference between true and magnetic heading

Which one of the followings is incorrect about magnetic compass?______.

A.The magentic compass is compulsory on my vessel

B.The magentic compass is prone to error

C.The magentic compass is always placed inside steel constructions

D.The magentic compass needs to be calibrated to compensate for local magnetic distortion

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

Magnetic compass deviation______．

A.varies depending upon the bearing used

B.is the angular difference between magnetic north and compass north

C.is published on the compass rose on most nautical charts

D.is the angular difference between geographic and magnetic meridians