Question

At a place in a town, the horizontal component of earth’s magnetic field is $2.5\text{G}$ and the angle of dip at that place is ${60}^{\circ }$. The magnetic field of earth at this location is?

• A. $1.25\text{G}$
• B. $3\text{G}$
• C. $2.25\text{G}$
• D. $5\text{G}$

Answer 1

The correct option is D $5\text{G}$

Given: $H=2.5\text{G},\delta ={60}^{\circ }$

Since, we know that, $\cos \delta =\frac{H}{B}$
Therefore, $H=B\cos \delta$

So, $2.5=B\times \cos {60}^{\circ }$
i.e. $B=5\text{G}$