Step 1: Define the angle of dip. The angle of dip, or magnetic inclination, is the angle made by the Earth's total magnetic field with the horizontal plane. It is denoted by \( \theta \).
Step 2: Relationship between horizontal and vertical components. At the location where the vertical (\( B_v \)) and horizontal (\( B_h \)) components of the magnetic field are equal, the tangent of the angle of dip (\( \theta \)) equals 1.
This is because: \[ \tan(\theta) = \frac{B_v}{B_h} \] When \( B_v = B_h \), \( \tan(\theta) = 1 \), which corresponds to an angle \( \theta = 45^\circ \).