When two magnetic moments are compared using the equal distance method,the deflections produced are $45^\circ$ and $30^\circ$. If the lengths of the magnets are in the ratio $1:2$,the ratio of their pole strengths is:

The ratio of magnetic moments of two bar magnets is $13 : 5$. These magnets are held together in a vibration magnetometer and are allowed to oscillate in the Earth's magnetic field. When like poles are together,$15$ oscillations per minute are made. What will be the frequency of oscillation of the system if unlike poles are together? (in $oscillations/min$)

The magnet of a vibration magnetometer is heated so as to reduce its magnetic moment by $19\%$. By doing this,the periodic time of the magnetometer will

Which curve best represents the relationship between current $i$ and deflection $\theta$ in a tangent galvanometer?

$A$ bar magnet of length $14 \, cm$ is placed in the magnetic meridian with its north pole pointing towards the geographic north pole. $A$ neutral point is obtained at a distance of $18 \, cm$ from the center of the magnet. If $B_{H} = 0.4 \, G$,the magnetic moment of the magnet is $\left(1 \, G = 10^{-4} \, T\right)$.

The frequency of vibration in a vibration magnetometer of the combination of two bar magnets of magnetic moments $M_1$ and $M_2$ is $6 \ Hz$ when like poles are tied together and it is $2 \ Hz$ when the unlike poles are tied together,then the ratio $M_1: M_2$ is