What is the orientation of the lines of flux when the inclination at the magnetic poles is 90°?

What is the orientation of the lines of flux when the inclination at the magnetic poles is 90°?

• A. Vertical
• B. Horizontal
• C. Diagonal
• D. Circular

Answer: (A)

The key idea is that magnetic inclination tells how much the field tilts from horizontal. An inclination of 90° means the magnetic field is perpendicular to the surface, so the lines of flux run straight vertical—entering the Earth at one pole and leaving at the other. As you move toward the equator, the inclination drops toward 0°, and the lines tilt toward horizontal. So the vertical orientation best matches a 90° inclination.

The key idea is that magnetic inclination tells how much the field tilts from horizontal. An inclination of 90° means the magnetic field is perpendicular to the surface, so the lines of flux run straight vertical—entering the Earth at one pole and leaving at the other. As you move toward the equator, the inclination drops toward 0°, and the lines tilt toward horizontal. So the vertical orientation best matches a 90° inclination.