Earth's magnetic field always has a horizontal component except at,or the horizontal component of Earth's magnetic field remains zero at:

The Earth's magnetic field at a certain place has a horizontal component of $0.3 \ G$ and the total strength of $0.5 \ G$. The angle of dip is:

Assume the dipole model for Earth's magnetic field $B$,which is given by:
$B_{V} = \text{vertical component of magnetic field} = \frac{\mu_{0}}{4\pi} \frac{2m \cos \theta}{r^{3}}$
$B_{H} = \text{horizontal component of magnetic field} = \frac{\mu_{0}}{4\pi} \frac{m \sin \theta}{r^{3}}$
where $\theta = 90^{\circ} - \text{latitude}$ as measured from the magnetic equator.
$(a)$ Find the loci of points for which $|\vec{B}|$ is minimum.

$A$ line passing through places having zero value of magnetic dip is called

The lines of force due to the Earth's horizontal component of the magnetic field are:

The pole near the geographic north pole is called ...... . The pole near the geographic south pole is called ...... .