Question

The angle of the dip at a place is 40.6${}^o$ and the vertical component of the earths magnetic field $B_V=6\times {10}^{-5}T$. The total intensity of the earth's magnetic field at this place is:

• A. $7\times 10$ ${}^{-5}$T
• B. $6\times 10$ ${}^{-5}$T
• C. $5\times 10$ ${}^{-5}$T
• D. $9.2\times 10$ ${}^{-5}$T

Answer 1

The correct option is D $9.2\times 10$ ${}^{-5}$T

$B\sin \theta =B_v$
$B=\frac{B_v}{\sin \theta }$
$B=\frac{6\times {10}^{-5}}{\sin {40.6}^{\circ }}$
$B=9.2\times {10}^{-5}T$