Question

Horizontal components of Earth's field is $3\times {10}^{-5}T$ and the angle of dip is ${53}^0$. Find the magnetic field of Earth at that place :

• A. $4\times {10}^{-5}T$
• B. $3\times {10}^{-5}T$
• C. $5\times {10}^{-5}T$
• D. $1\times {10}^{-5}T$

Answer 1

Answer: (C)

$5\times {10}^{-5}T$

Horizontal component of earth's magnetic field,
$B_H=B\cos \delta$ or
Magnetic field of earth $B=\frac{B_H}{\cos \delta }=\frac{3\times {10}^{-5}}{3/5}=5\times {10}^{-5}T.$