Question

If a magnet is suspended at an angle 30${}^0$ to the magnetic meridian, the dip needle makes an angle of ${60}^o$ with the horizontal. The true value of dip is :

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

Answer 1

The correct option is B $ta{n}^{-1}\left(3/2\right)$

Given the apparent dip is ${\delta }_1={60}^o$
Angle made by the magnet with the magnetic meridian is $\theta ={30}^o$
$tan{\delta }_1=\frac{tan\delta }{cos\theta }$
$tan\delta =tan(60{)}^o\times cos(30{)}^o$
True dip is $\delta =ta{n}^{-1}(\frac{3}{2})$