Question

Describe the elements of earth's magnetic field

Answer 1

The elements are:
Magnetic declination (q)
Magnetic inclination (d)
Horizontal component (BH)
​Magnetic declination:
The small angle between magnetic axis and geographic axis at a place is defined as magnetic declination at that place. It is represented by θ.

Magnetic Inclination:
Magnetic dip, dip angle, or magnetic inclination is the angle made with the horizontal by the compass needle of a vertically held compass. 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. The value can be measured with an instrument typically known as a dip circle.
(1)At equator the magnetic field is parallel to the horizon so there will be zero angle of dip.
(2) At poles the magnetic field is almost vertical, here the dip will me maximum.

Horizontal component :
It is the component of earth’s magnetic field along the horizontal direction.
So the angle of dip is the angle between earth’s magnetic field i.e. B and the horizontal component i.e. BH.