Question

For the terrestrial magnetism establish a relation between angle of dip $\theta$, horizontal component $H$ and vertical component $V$.

Answer 1

Let $I$ be the total intensity of earths field and $\theta$ be the angle of dip.

$\therefore$ Resolving $I$ in two perpendicular direction we get Horizontal component $=I\cos \theta$ and vertical component $=I\sin \theta$

or $H=I\cos \theta$ ....(i)

and $V=I\sin \theta$ .....(ii)

$\therefore$ Dividing equation (ii) by equation (i) we get

$\frac{V}{H}=\frac{I\sin \theta }{I\cos \theta }$

$\frac{V}{H}=\tan \theta$ .....(iii)

or $\tan \theta =\frac{V}{H}$