Question

The angle of inclination of the axis of the magnetic needle to the horizontal plane when suspended freely and is at rest is known as

• A. Angle of inclination
• B. Angle of variation
• C. Angle of declination
• D. None of the above

Answer 1

Answer: (A)

Angle of inclination

Magnetic dip or magnetic inclination is the angle made with the horizontal by the Earth's magnetic lines of force. This angle varies at different points on the Earth's surface. Positive values of inclination indicate that the magnetic field of the Earth is pointing downward, into the Earth, at the point of measurement, and negative values indicate that it is pointing upward. The dip angle is in principle the angle made by the needle of a vertically held compass, though in practice ordinary compass needles may be weighted against dip or may be unable to move freely in the correct plane. The value can be measured more reliably with a special instrument typically known as a dip circle.