IOP. General Navigation

The term 'ellipsoid' may be used to describe:

• a) a great circle on the celestial sphere.

• b) the shape of the ecliptic.

• c) the movement of the Earth around the Sun.

• d) the shape of the Earth.

The circumference of the Earth is approximately:

• a) 43.200 NM

• b) 10.800 NM

• c) 21.600 NM

• d) 5.400 NM

The Earth is:

• a) a sphere whose centre is equidistant (the same distance) from the Poles and the

  Equator.

• b) a sphere which has a larger polar circumference than equatorial circumference.

• c) none of the above statements is correct.

• d) considered to be a perfect sphere as far as basic (simple) navigation is

  concerned.

Seasons are due to the:

• a) Earth's rotation on its polar axis.

• b) Earth's elliptical orbit around the Sun.

• c) variable distance between Earth and Sun.

• d) inclination of the polar axis with the ecliptic plane.

The poles on the surface of the Earth may be defined as:

• a) the points on the surface of the Earth where all meridians intersect at right angles.

• b) the points where the Earth's axis of rotation penetrates the surface of the

  Earth.

• c) the points at which the vertical lines runs through the centre of the Earth.

• d) the points from where the distance to the equator is equal.

When the Sun's declination is northerly:

• a) midnight Sun may be observed at the south pole.

  b) it is winter on the northern hemisphere.

• b) it is winter on the northern hemisphere.

• d) the daylight period is shorter in the southern hemisphere than the northern.

• c) the sunrise occurs earlier at southern latitudes than the northern latitudes.

Consider the positions (00°N/S, 000°E/W) and (00°N/S, 180°E/W) on the ellipsoid.

Which statement about the distances between these positions is correct?

• a) The route via the equator is shorter than the route via the South Pole.

• b) The route via the North Pole is shorter than the route along the equator.

• c) The route via either pole and the route via the equator are of equal length.

• d) The route via the South pole is shorter than the route via the North Pole.

The maximum difference between geocentric and geodetic latitude occurs at about:

• a) 60° North and South.

• b) 90° North and South.

• c) 0° North and South (equator).

• d) 45° North and South.

What is difference in latitude from 30°39'S-20°20'E to 45°23'N-40°40'E:

• a) 14°44'N

• b) 76°2'N

• c) 76°2'S

• d) 14°44'S

Given: A (56°N , 145°E); B (57°N , 165°W). What is the difference in longitude

between A and B?

• a) 020°

• b) 050°

• c) 001°

• d) 130°