What is the difference between grid north and magnetic north known as?

• A. Magnetic declination
• B. True north
• C. Geographic north
• D. Celestial north

Answer: (A)

The difference between grid north and magnetic north is known as magnetic declination. Magnetic declination refers to the angle between true north, which is based on the Earth's geographic poles, and magnetic north, which is where a magnetic compass points. This difference varies depending on where you are on the Earth's surface and changes over time due to shifts in the Earth's magnetic field.

Understanding magnetic declination is essential for navigation and map reading, particularly when using topographical maps, which often use grid north as the reference. To navigate accurately, one must adjust for this declination to ensure that they are aligning their compass correctly with the map.

The other options pertain to different concepts. True north refers to the direction along the Earth's surface towards the North Pole. Geographic north is synonymous with true north and does not address the difference in declination. Celestial north is not a standard term used in navigation and does not relate to the compass system directly.