Question

At a certain place, the angle of dip is ${30}^{\circ }$ and the horizontal component of earth's magnetic field is $0.50\text{Oersted}.$ The earth's total magnetic field is (in $\text{Oersted}$)

• A. $\sqrt{3}$
• B. $1$
• C. $\frac{1}{\sqrt{3}}$
• D. $\frac{1}{2}$

Answer 1

The correct option is C $\frac{1}{\sqrt{3}}$

Horizontal component of earth’s magnetic field is given by,

$B_H=B\cos \varphi$,

$\therefore B=\frac{B_H}{\cos \varphi }=\frac{0.5}{\cos {30}^{\circ }}=\frac{0.5}{\frac{\sqrt{3}}{2}}=\frac{1}{\sqrt{3}}$

<!--td {border: 1px solid #ccc;}br {mso-data-placement:same-cell;}--> Hence, $\left(C\right)$ is the correct answer.