From which item should you keep 18 meters distance from a compass?

From which item should you keep 18 meters distance from a compass?

• A. Field gun, truck, or tank: 18 meters
• B. High tension power lines: 55 meters
• C. Telephone wires and barbed wire: 10 meters
• D. Machine gun: 2 meters

Answer: (A)

Magnetic interference from nearby metal objects and electrical sources can distort a compass reading, so you must keep safe distances from potential magnetic sources to get an accurate bearing. A field gun, truck, or tank has a large metal mass and significant magnetic signature, so staying about 18 meters away minimizes the needle deviation and helps you read true direction rather than being pulled by the vehicle’s metal and any residual magnetism. The other options require different distances because their magnetic influence or hazards differ: high-tension power lines create a stronger magnetic field and thus need a much greater clearance (about 55 meters), telephone wires and barbed wire are less influential (around 10 meters), and a machine gun, being smaller, requires only a shorter separation (about 2 meters).

Magnetic interference from nearby metal objects and electrical sources can distort a compass reading, so you must keep safe distances from potential magnetic sources to get an accurate bearing. A field gun, truck, or tank has a large metal mass and significant magnetic signature, so staying about 18 meters away minimizes the needle deviation and helps you read true direction rather than being pulled by the vehicle’s metal and any residual magnetism. The other options require different distances because their magnetic influence or hazards differ: high-tension power lines create a stronger magnetic field and thus need a much greater clearance (about 55 meters), telephone wires and barbed wire are less influential (around 10 meters), and a machine gun, being smaller, requires only a shorter separation (about 2 meters).