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:

Let $V$ and $H$ be the vertical and horizontal components of the Earth's magnetic field at any point on Earth. Near the North Pole:

$A$ dip circle is adjusted so that its needle moves freely in the magnetic meridian. In this position,the angle of dip is $40^{\circ}$. Now the dip circle is rotated so that the plane in which the needle moves makes an angle of $30^{\circ}$ with the magnetic meridian. In this position,the needle will dip by an angle:

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

The Earth's magnetic field at the equator is approximately $0.4 \, G$. Calculate the Earth's magnetic dipole moment (nearly). (Radius of Earth $R = 6.4 \times 10^6 \, m$)

At an angle of $30^{\circ}$ to the magnetic meridian,the apparent dip is $45^{\circ}$. Find the true dip.