These are just some of the questions on the Coast Guard exam for Navigation General. This is just one of subjects required for a merchant marine license.
1. The GHA of a star ?
A. Increases at a rate of approximately 15° per hour
B. Increases at a rate of approximately 4° per hour
C. Decreases at a rate of approximately 15° per hour
D. Decreases at a rate of approximately 4° per hour
2. In the celestial equator system of coordinates what is equivalent to the longitude of the Earth system of coordinates?
A. Zenith distance
B. Azimuth angle
C. Declination
D. Greenwich hour angle
3. In the celestial equator system of coordinates what is the equivalent to the meridians of the Earth system of coordinates?
A. Horizon
B. Hour circles
C. Vertical circles
D. Parallel of declination
4. In the celestial equator system of coordinates what is equivalent to the colatitude of the Earth system of coordinates?
A. Coaltitude
B. Zenith distance
C. Polar distance
D. Declination
5. If the right ascension of a body is 9 hours, it also?
A. Is 135°
B. Corresponds to an SHA for the body of 45°
C. Means that the GP of the body is in the western hemisphere
D. All of the above
6. The GHA of the first point of Aries is 315° and the GHA of a planet is 150°. What is the right ascension of the planet?
A. 7 hours
B. 11 hours
C. 19 hours
D. 23 hours
7. The angle measured eastward from the vernal equinox along the celestial equator often expressed in time units?
A. Greenwich sidereal time
B. Right ascension
C. Local sideral time
D. Sideral hour angle
8. Right ascension is primarily used by the navigator for?
A. Calculating amplitudes
B. Calculating great circle sailing by the Agiton method
C. Entering the Air Navigation Tables (Selected Stars) Pub. 249
D. Plotting on star finders
9. The ecliptic is?
A. The path the Sun appears to take among the stars
B. The path the Earth appears to take among the stars
C. a diagram of the zodiac
D. a great circle on a gnomonic chart
10. The navigator is concerned with three systems of coordinates. Which system is not of major concern?
A. Terrestrial
B. Ecliptic
C. Celestial horizon
D. Celestial equator
11. The equator is?
A. The primary great circle of the Earth perpendicular to the axis
B. The line to which all celestial observations are reduced
C. The line from which a celestial body's altitude is measured
D. All of the above
12. The angle at the pole measured through 180° from the prime meridian to the meridian of a point is known as?
A. The departure
B. The polar arc
C. Longitude
D. Greenwich hour angle
13. A plane perpendicular to the polar axis will never form what line on the Earth's surface?
A. Great circle
B. Equator
C. Small circle
D. Meridian
14. A plane that cuts the Earth's surface at any angle and passes through the center will always form?
A. the equator
B. a great circle
C. a small circle
D. a meridian
15. A plane that cuts the Earth's surface and passes through the poles will always form?
A. the equator
B. a loxodromic curve
C. a small circle
D. a meridian
16. When correcting apparent altitude to observed altitude, you do NOT apply a correction for?
A. The equivalent reading to the center of the body
B. The equivalent reading from the center of the Earth
C. The bending of the rays of light from the body
D. Inaccuracies in the reference level
17. When applying a dip correction to the sighted sextant angle (hs), you always subtract the dip because you are correcting?
A. hs to the visible horizon
B. hs to the sensible horizon
C. hs to the celestial horizon
D. Ho to the celestial horizon
18.The height of eye correction is smaller than geometrical dip because of?
A. The angle between the horizontal and the line of sight to the visible horizon
B. Index error
C. Parallax
D. Terrestrial refraction
19. A semidiameter correction is applied to observations of ?
A. Mars
B. The Moon
C. Jupiter
D. All of the above
20.The diameter of the Sun and Moon as seen from the Earth varies slightly but averages about?
A. 1'
B. 52'
C. 32'
D. 15.5'
