Magnetic meridian is a

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 the dip angle is $\pm 45^{\circ}$.

At two different places,the angles of dip are respectively $30^{\circ}$ and $45^{\circ}$. At these two places,the ratio of the horizontal component of Earth's magnetic field is:

The total intensity of the Earth's magnetic field at the magnetic equator is $5$ $units$. Its value at a magnetic latitude of $37^{\circ}$ is equal to:

The angle of dip at a place is $60^{\circ}$. At this place,the total intensity of the Earth's magnetic field is $0.64 \text{ units}$. The horizontal intensity of the Earth's magnetic field at this place is . . . . . . $\text{units}$.

At a place,if the earth's horizontal and vertical components of magnetic fields are equal,then the angle of dip will be.......$^o$