Question

The horizontal component of the Earth's magnetic field is $3.6\times 10^{- 5 \, } \, T$ where the dip angle is $60^\circ $ . The magnitude of the Earth's magnetic field is

• A. $2.8\times 10^{- 4}tesla$
• B. $2.1\times 10^{- 4}tesla$
• C. $7.2\times 10^{- 5}tesla$
• D. $3.6\times 10^{- 5}tesla$

Answer 1

Answer: (C)

Horizontal component of Earth’s field,
$H = B cos \theta ,$ since, $\theta =60^\circ $

$3.6 \times 10^{- 5} = B \times \frac{1}{2} \Rightarrow B = 7.2 \times 10^{- 5}$ $tesla$