At a place, where the true dip is $45°,$ the apparent dip is $60°.$ In a plane perpendicular to the previous plane, what would be the apparent dip ?

Earth's magnetic field may be imagined to be due to a small bar magnet located at the centre of the earth. If the magnetic field at a point on the magnetic equator is $0.3\times {10}^{-4} \mathrm{T},$ what is the moment of such a bar magnet? What is the value of the magnetic field at the north pole? (radius of the earth$=6.4\times {10}^6 \mathrm{m}$)

Find the magnetic moment of the magnet if the earth's horizontal magnetic field is $20\mu \mathrm{T}.$

The needle of a deflection magnetometer deflects through $45°$ from north-south when the instrument is used in Tan-A position with a magnet of length $8 \mathrm{cm}$ placed at a distance of $20 \mathrm{cm}$

The needle of a deflection magnetometer deflects through $45°$ from north-south when the instrument is used in Tan-A position with a magnet placed at a distance of $20 cm$ and length $8 \mathrm{cm}$

Find the magnetic moment of the magnet if the earth's horizontal magnetic field is $20\mu \mathrm{T}.$

Three magnets of same length but moments $M,2M$ and $3M$ are arranged in the form of an equilateral triangle with opposite poles nearer, the resultant magnetic moment of the arrangement is: