Question 671Navigation General

The correct answer is B) magnetic equator. The magnetic equator is the line connecting the points on the Earth's surface where the magnetic dip angle (the angle between the Earth's magnetic field and the horizontal plane) is zero. This line, also known as the aclinic line, represents the area where the Earth's magnetic field is horizontal, with no vertical component. The other answer choices are incorrect: A) isodynamic - This refers to a line connecting points with equal magnetic intensity, not zero dip angle. C) isopor - This term is not commonly used in the context of Earth's magnetic field. D) agonic line - This refers to a line connecting points with zero magnetic declination (the angle between true north and magnetic north), not zero dip angle.