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. $ta{n}^{-1}\frac{1}{2}$
  
• B. $ta{n}^{-1}\left(2\right)$
  
• C. $ta{n}^{-1}\left(\frac{2}{3}\right)$
• D. $Noneofthese$

Answer 1

The correct option is B $ta{n}^{-1}\left(2\right)$


$tan{\varphi }^{\prime }=\frac{tan\varphi }{cos\beta }$ ; where ${\varphi }^{\prime }=$Apparent angle of dip,
$\varphi$ = True angle of dip, $\beta$ =Angle made by vertical plane with magnetic meridian.
$\Rightarrow tan{\varphi }^{\prime }=\frac{tan{60}^{\circ }}{cos{30}^{\circ }}=2\Rightarrow {\varphi }^{\prime }=ta{n}^{-1}\left(2\right)$