The magnitude of the angle of dip at the equator is

Analysis

The question asks for the angle of dip at the Earth's magnetic equator. The angle of dip (or magnetic inclination) is the angle that a freely suspended magnetic needle makes with the horizontal surface of the Earth.

Concept Explanation

• Magnetic Dip: This is the angle between the Earth's magnetic field lines and the horizontal plane.
• At the Poles: The magnetic field lines are perpendicular to the Earth's surface. Therefore, a magnetic needle will point straight down (or up), resulting in an angle of dip of 90°.
• At the Equator: The magnetic field lines are parallel to the Earth's surface. Because the field lines run horizontally, a freely suspended magnetic needle will remain perfectly horizontal. Since there is no vertical component to the magnetic field at the equator, the angle between the needle and the horizontal is 0°.

Step-by-Step Solution

1. Identify the location: We are looking at the Earth's equator.
2. Determine the field orientation: At the equator, the Earth's magnetic field lines are horizontal.
3. Relate to the needle: A magnetic needle aligns itself with the magnetic field lines. If the field is horizontal, the needle stays horizontal.
4. Calculate the angle: The angle of dip is the angle between the horizontal and the needle. Since both are horizontal, the angle is 0°.

Conclusion

Exam Tip: Remember the mnemonic "E-Z": Equator = Zero degrees. Conversely, remember that the Poles are Perpendicular (90°). This will help you avoid mixing them up during your JAMB exam!