Question

The earth's magnetic field always has a vertical component except at the

• A. magnetic equator
• B. magnetic poles
• C. geographic north pole
• D. latitude $45^o$

Answer 1

Answer: (A)

Let $\theta$ be the angle of dip at a place.
Then,
$sin\left(\theta \right)=\frac{B_V}{B}$ and $cos\left(\theta \right)=\frac{B_H}{B}$
At magnetic equator angle of dip becomes zero.
So, the total magnetic field at the equator becomes a horizontal component $\left(B_H=B\right)$ and the vertical component becomes zero $\left(B_V=0\right)$ .