Question

Choose the correct option :

• A. True dip is not mathematically related to apparent dip.
• B. True dip is always equal to the apparent dip.
• C. True dip is always greater than the apparent dip.
• D. True dip is less than apparent dip.

Answer 1

The correct option is D True dip is less than apparent dip.

If apparent dip circle is at an angle $\alpha$ with true dip
circle then,



Now, for apparent dip angle,

$\tan {\varphi }^{\prime }=\frac{B_V}{B_H\cos \alpha }$

$\Rightarrow \tan {\varphi }^{\prime }=\frac{B_H\tan \varphi }{B_H\cos \alpha }=\frac{\tan \varphi }{\cos \alpha }$

As, $\cos \alpha <1$

$\therefore \text{True dip angle}\left(\varphi \right)<\text{Apparent dip angle}\left({\varphi }^{\prime }\right)$

Hence, $\left(B\right)$ is the correct answer.