Question

The angle between the true north-south line and the magnetic north south line is known as ____________.

• A. magnetic bearing
• B. magnetic variation
• C. magnetic declination
• D. true bearing

Answer 1

The correct option is C magnetic declination

The angle between the true north-south line and the magnetic north south line is known as magnetic declination.

Magnetic declination, or magnetic variation, is the angle on the horizontal plane between magnetic north (the direction the north end of a magnetized compass needle points, corresponding to the direction of the Earth's magnetic field lines) and true north (the direction along a meridian towards the geographic North Pole). This angle varies depending on position on the Earth's surface and changes over time.

Somewhat more formally, Bowditch defines variation as “the angle between the magnetic and geographic meridians at any place, expressed in degrees and minutes east or west to indicate the direction of magnetic north from true north. The angle between magnetic and grid meridians is called grid magnetic angle, grid variation, or grivation.