The angle between the geographic and the magnetic meridians at a place on the earth’s surface is the

Step 1: Analyze the question The question asks for the name of the angle between two vertical planes at a place: the geographic meridian (which points to true north) and the magnetic meridian (which points to magnetic north, the direction a compass needle settles in).

Step 2: Explain the concept The Earth's magnetic poles do not coincide with its geographic poles. Because of this, a compass needle does not point exactly to true north. Two angles describe the Earth's magnetic field at a place:

• Angle of declination (variation): the angle between the geographic meridian and the magnetic meridian. It is measured in the horizontal plane.
• Angle of dip (inclination): the angle between the Earth's total magnetic field and the horizontal. It is measured in the vertical plane, using a dip circle.

Step 3: Check each option

• A. Angle of declination: correct. It is defined as the angle between the geographic and magnetic meridians.
• B. Angle of depression: this is an optics and trigonometry term for the angle below the horizontal when looking down. It has nothing to do with magnetism.
• C. Angle of dip: this is the angle between the magnetic field and the horizontal, not between the meridians.
• D. Latitude: the angular position north or south of the equator.
• E. Longitude: the angular position east or west of the Greenwich meridian.

Step 4: Answer The angle between the geographic and magnetic meridians is the angle of declination, which is option A.

Exam tip: Remember "DeCLINation = Compass vs. true north" (horizontal difference between the two norths), and "DIP = Dive of the field" (the field tilts down into the earth). Declination is about the meridians, and dip is about the horizontal.