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:

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:

$A$ magnet is suspended in such a way that it oscillates in the horizontal plane. It makes $20$ oscillations per minute at a place where the dip angle is $30^{\circ}$ and $15$ oscillations per minute at a place where the dip angle is $60^{\circ}$. The ratio of the total Earth's magnetic field at the two places is:

$A$ long vertical wire carries a steady current of $5.0 \, A$. $A$ sensitive magnetic compass is placed in a plane perpendicular to the wire and $10.0 \, cm$ south of it. It registers a deflection of $60^{\circ}$ north of east. The magnitude of the horizontal component of the earth's magnetic field is (permeability of free space is $4 \pi \times 10^{-7} \, N/A^2$):

If the dip circle is set at $45^{\circ}$ to the magnetic meridian,then the apparent dip is $30^{\circ}$. The true dip of the place is:

Assertion : The true geographic north direction is found by using a compass needle.
Reason : The magnetic meridian of the earth is along the axis of rotation of the earth.