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

In India,the magnetic declination at Delhi is . . . . . . .

The plane of a dip circle is set in the geographic meridian and the apparent dip is $\delta_1$. It is then set in a vertical plane perpendicular to the geographic meridian. The apparent dip angle is $\delta_2$. The declination $\theta$ at the place is

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:

Two bar magnets with magnetic moments $2M$ and $M$ are fastened together at right angles to each other at their centres to form a crossed system,which can rotate freely about a vertical axis through the centre. The crossed system sets in the Earth's magnetic field with the magnet having magnetic moment $2M$ making an angle $\theta$ with the magnetic meridian such that:

At the magnetic north pole of the earth, the value of the horizontal component of the earth's magnetic field and the angle of dip are, respectively: