The angle which the axis of needle makes with the horizontal, is called angle of dip (θ). In other words, the angle of dip at a place is the angle which the resultant magnetic field of earth at that place makes with the horizontal.
![](https://www.sarthaks.com/?qa=blob&qa_blobid=7491418542438266308)
In fig. AC shows the direction of resultant magnetic field of earth and the angle BAC(=θ) between it and the horizontal AB is the angle of dip.