Question

Define the concept of magnetic inclination or angle of dip.

Answer 1

Hint: The concept of magnetic inclination occurs due to the orientation of earth’s magnetic field lines. The geographical north-pole and the magnetic north pole formed due to earth’s magnetic line do not align with each other. They are a bit apart.

Complete step-by-step solution:

The geographic North Pole is where the earth’s latitude is 90° and is where the earth’s axis of rotation is. The magnetic north pole is where all the field lines are downward, it appears as if the field lines emerge from the poles.

A compass typically points us towards the magnetic north pole.

If we consider a horizontal surface on earth, at that point the magnetic field lines of earth that pass through the surface make some angle φ with the surface. This angle is called the magnetic inclination or the angle of dip.

If the angle of dip is positive that means the magnetic lines are pointing towards the earth and if they are pointing upwards the angle of dip is negative. 

If both the horizontal and vertical components of earth’s magnetic lines are equal then the angle of dip is 45°.

The angle of dip varies from 90° at the North Pole till -90° at the South Pole.

The angle of dip at the equator is 0°, here the earth’s magnetic field lines go along the surface.

At any other place on the earth the angle of dip is somewhere between 0° and 90°.

Note:  In order to answer this type of question the key is to know the concept of the magnetic field of earth. Earth does not have any electricity inside it to create a magnetic field around it but the core or the innermost part of the earth is made up of liquid iron and nickel. This creates electric currents which are responsible for earth’s magnetism.