Question 643Navigation General

70% to pass

If a magnetic compass is not affected by any magnetic field other than the Earth's, which statement is TRUE?

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

The correct answer is C) Compass error and variation are equal. If a magnetic compass is not affected by any magnetic field other than the Earth's, then the only compass error present would be variation - the angle between true north and magnetic north. Since there is no deviation (error caused by local magnetic fields), the compass error and variation would be equal. The other options are incorrect because: A) Compass north will not be true north if variation is present; B) Variation and deviation are separate compass errors; and D) There will be compass error (variation) if the Earth's magnetic field is the only one affecting the compass.

Related Questions
Q@q.QuestionNumber:On the Western Rivers, a vessel crossing a river must _______________. Q@q.QuestionNumber:Error may be introduced into a magnetic compass by _______________. Q@q.QuestionNumber:The speed at which an ocean wave system advances is called _______________. Q@q.QuestionNumber:When a buoy marks a channel bifurcation, the preferred channel is NOT indicated... Q@q.QuestionNumber:The speed of an ocean current is dependent on _______________.

Ready to test your knowledge?

Take a Navigation General Practice Exam
Official Resources
USCG Navigation Rules (COLREGS) 33 CFR Navigation Rules USCG National Maritime Center
← Previous All Questions Next →

Want to practice with timed exams?

Download Coast Guard Exams for the full exam experience.

Get the App