Q. The angle of the dip at a place is 40.6° and the vertical component of the earths magnetic field BV = 6 × 10-5 T. The total intensity of the earth’s magnetic field at this place is (sin 40.6° = 0.65)
(a) 7 × 10-5 T
(b) 6 × 10-5 T
(c) 5 × 10-5 T
(d) 9.2 × 10-5 T
Ans: (d)
Solution: $ \displaystyle B_v = B sin\theta $
$ \displaystyle B = \frac{B_v}{sin\theta} $
$ \displaystyle B = \frac{6\times 10^{-5}}{sin 40.6} $
$\displaystyle B = \frac{6\times 10^{-5}}{0.65} $
= 9.2 × 10-5 T