Question

A dip needle lies initially in the magnetic meridian when it shows an angle of dip $ \theta $ at a place. The dip circle is rotated through an angle $ x $ in the vertical plane and then it shows an angle of dip $ \theta ' $ .Then $ \frac{\tan \theta '}{\tan \theta } $ is

• A. $ \frac{1}{\cos x} $
• B. $ \frac{1}{\sin x} $
• C. $ \frac{1}{\tan x} $
• D. $ \cos x $

Answer 1

Answer: (A)

In magnetic meridian, angle of dip is given by
$ \tan \theta =\frac{V}{H} $ ...(i)
When dip circle is rotated in vertical plane, then
$ \tan \theta '=\frac{V}{H\cos x} $
$ \therefore $ $ \frac{\tan \theta '}{\tan \theta }=\frac{1}{\cos x} $