Question

What do you mean by angle of inclination and horizontal component of magnetic field? Establish relations between them.

Answer 1

In order to solve this question we need to understand the magnetic field. Magnetic field or magnetic line of forces are those fields in which if any other magnetic material were placed, it would experience magnetic force. In any magnetic materials, there are two sides or two poles, one is North Pole and other is South Pole. These North Pole and South Pole forms a pair and creates magnetic field lines. Magnetic field lines are always circular in nature hence their flux of magnetic field through closed surface is always zero.

Complete answer:
Like any other magnetic material, earth two has two poles one is North Pole and other is South Pole which forms the magnetic field lines of earth, hence a magnetic field exists on earth. Now to measure this magnetic field, a magnetic compass is made which one holds vertically, then it’s magnetic needle makes some angle with horizontal, this angle is known as angle of inclination. It is denoted as $\delta$

Horizontal component of earth’s magnetic field is defined as component of earth’s magnetic field which is in horizontal direction. And it is denoted as ${B_H}$.
The relation between them;
Since from figure,
$\cos \delta = \dfrac{{{B_H}}}{B}$
$\therefore {B_H} = B\cos \delta$
Here, “B” is the earth's magnetic field.

Note: It should be remembered that, angle of inclination can be positive or negative depending upon earth’s magnetic field. If earth’s magnetic field points inward then angle of inclination is positive and if magnetic field goes in upward direction then angle of inclination is negative. Also earth’s magnetic field is not constant, rather earth keeps inverting its poles from time to time.