A magnet is suspended in the magnetic meridian with an untwisted wire. The upper end of wire is rotated through $180^o$ to deflect the magnet by $30^o$ from magnetic meridian. When this magnet is replaced by another magnet, the upper end of wire is rotated through $ 270^o$ to deflect the magnet $30^o$ from magnetic meridian. The ratio of magnetic moments of magnets is
$1:5$
$1:8$
$5:8$
$8:5$
The angle between the magnetic meridian and geographical meridian is called
Consider the plane $\mathrm{S}$ formed by the dipole axis and the axis of earth. Let $\mathrm{P}$ be point on the magnetic equator and in $\mathrm{S}$. Let $\mathrm{Q}$ be the point of intersection of the geographical and magnetic equators. Obtain the declination and dip angles at $\mathrm{P}$ and $\mathrm{Q}$
The lines of forces due to earth's horizontal component of magnetic field are
A dip circle lies initially in the magnetic meridian, it shows an angle of dip $\delta$ at a place. The dip circle is rotated through an angle $\alpha$ in the horizontal plane and then it shows an angle of dip $\delta^{\prime}$. Hence $\frac{\tan \delta^{\prime}}{\tan \delta}$ is
A compass needle will show which one of the following directions at the earth's magnetic pole