Question

The true value of angle of dip at a place is $60^\circ$, the apparent dip in a plane inclined at an angle of $30^{\circ}$ with magnetic meridian is

• A. $\tan^{-1}\frac{1}{2}$
• B. $\tan^{-1}2$
• C. $\tan^{-1}\frac{2}{3}$
• D. none of these

Answer 1

Answer: (B)

$\tan^{-1}2$

Answer 2

True value of angle of dip, $\phi = 60^{\circ}$ and Angle of inclination of plane, $\alpha = 30^{\circ}$ Let apparent dip be $\delta$, then tan $\delta$, = $\frac{tan \, \phi}{cos \, \alpha} = \frac{tan \,60^{\circ} }{cos \,30^{\circ} } = \frac{\sqrt{3}}{\sqrt{3} /2} = 2$ $\delta = tan^{-1}2$