Gnav4

If the CH = 220°, Variation = 12°E, Deviation = 2°W, what is the corresponding TH?

• TH = 234°

• TH = 206°

• TH = 230°

• TH = 210°

The long term periodic change in the Earth's Magnetic Field

• is caused by sunspot activity.

• is caused by the westerly movement of the geographic North Pole.

• affects mainly the compass deviation.

• is reflected in the slow movement of the magnetic poles.

What is meant by "Aphelion"?

• The point of the Sun's orbit furthest away from the Earth.

• The point of the Sun's orbit closest to the Earth.

• The point of the Earth's orbit furthest away from the Sun.

• The point of the Earth's orbit closest to the Sun.

Deviation applied to magnetic heading gives:

• magnetic course.

• magnetic track.

• true heading.

• compass heading.

When the time is 20:00 UTC, it is:

• 14:00 LMT at 90° West.

• 24:00 LMT at 120° West.

• 12:00 LMT at 60° East.

• 08:00 LMT at the Prime meridian.

In a sunrise/sunset table given for the 28th of june at a certain latitude, sunrise is given as 0239 and sunset is given as 2127. What is the latitude?

• 55°S

• 60°N

• 80°N

• 00°N/S

The Directive Force:

• is zero over the geographical poles.

• equals the vertical component of the Earth's magnetic field.

• is about twice as strong on 60°N/S as on the Equator.

• is the component of the Earth's magnetic field which aligns the compass needle.

Generally what line lies closer to the pole?

• Rhumb line.

• Orthodromic line.

• Equator.

• The rhumb line or great circle depending on the chart used.

What is the definition of "morning civil twilight"?

• The period in the morning. just before sunrise.

• The period of semi-darkness in morning.

• Morning civil twilight is the period in the morning from the centre of the Sun is 6° below the horizon until the upper limb of the Sun appears at the horizon.

• The period when the Sun, in the morning, has its centre between 6° under the horizon and the horizon.

Position A is located on the equator at longitude 130°00'E. Position B is located 100 NM from A on a bearing of 225° (T). The coordinates of position B are:

• (01°11'N - 128°49'E)

• (01°11 'S - 128°49'E)

• (01°11'N - 131°11'E)

• (01°11'S - 131°11'E)