Lines which represent places of constant angle of dip are called

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

At a certain place the angle of dip is $30°$  and the horizontal component of earth's magnetic field is $0.50$  Oersted. The earth's total magnetic field is

Intensity of magnetic field due to earth at a point inside a hollow steel box is

If a magnet is suspended at an angle $30^o$ to the magnetic meridian, it makes an angle of $45^o$ with the horizontal. The real dip is

Two bar magnets oscillate in a horizontal plane in earth's magnetic field with time periods of $3\,s$ and $4\,s$ respectively. If their moments of inertia are in the ratio of $3: 2$ then the ratio of their magnetic moments will e.