The device for measuring the angle of dip is

Analysis of the Question

The question asks for the specific scientific instrument used to measure the "angle of dip" (also known as magnetic inclination). This is a fundamental concept in the study of Earth's magnetism in Physics.

Explanation of the Concept

The angle of dip is the angle that the Earth's magnetic field makes with the horizontal at any point on the Earth's surface.

• At the magnetic equator, the angle of dip is 0°.
• At the magnetic poles, the angle of dip is 90°.

To measure this angle, we need a device that allows a magnetic needle to rotate freely in a vertical plane. This device is specifically designed to balance the needle so that it can align itself with the Earth's magnetic field lines relative to the horizon.

Step-by-Step Solution

1. Identify the purpose: We are looking for an instrument that measures vertical magnetic inclination.
2. Evaluate the options: • Dip circle: This is the standard laboratory instrument consisting of a magnetic needle mounted on a horizontal axis, which can rotate freely in a vertical plane. It is specifically calibrated to measure the angle of dip. • Dip inclination: This is a term describing the phenomenon itself, not a physical device. • Dip variation: This refers to the change in the angle of dip over time or location, not a measuring instrument. • Dip meter: While this sounds like a measuring device, it is not the standard terminology used in Physics textbooks (like the WAEC/JAMB syllabus) for this specific instrument.

Conclusion

The correct instrument used in Physics to measure the angle of dip is the Dip circle.

Exam Tip

When studying magnetism, remember the difference between these two:

• Magnetic Declination: Measured using a Compass (horizontal angle).
• Magnetic Dip (Inclination): Measured using a Dip Circle (vertical angle).