In land navigation, magnetic declination is the angular difference between which two terms?

• A. True north and grid north
• B. True north and magnetic north
• C. Grid north and magnetic north
• D. True north and east

Answer: (B)

Magnetic declination is the angular difference between true north (geographic north) and magnetic north (the direction the compass needle points). This matters because a compass aligns with magnetic north, while most maps are oriented to true north, so you adjust readings to match your map by using the declination value. The angle between true north and grid north is grid convergence, not magnetic declination, and the angle between grid north and magnetic north is a different reference, while the angle involving east isn’t the navigation angle in this context. So the statement that magnetic declination is the angle between true north and magnetic north is the correct description. For practical use, you add or subtract this angle from your compass bearing to obtain a true bearing, depending on your location and the sign of the declination.