At a certain place, a magnet makes $30$ oscillations per minute. At another place where the magnetic field is double, its time period will be:

$A$ bar magnet of moment of inertia $49 \times 10^{-2} \,kg-m^2$ vibrates in a magnetic field of induction $0.5 \times 10^{-4} \,T$. The time period of vibration is $8.8 \,s$. The magnetic moment of the bar magnet is (in $\,A-m^2$)

$A$ vibration magnetometer consists of two identical bar magnets placed one over the other such that they are perpendicular and bisect each other. The time period of oscillation in a horizontal magnetic field is ${2^{5/4}} \ s$. One of the magnets is removed and if the other magnet oscillates in the same field,then the time period in seconds is

$A$ neutral point is obtained at the centre of a vertical circular coil carrying current. The angle between the plane of the coil and the magnetic meridian is.......$^o$

Two tangent galvanometers,which are identical except in their number of turns,are connected in parallel. The ratio of their resistances of the coils is $1 : 3$. If the deflections in the two tangent galvanometers are $30^{\circ}$ and $60^{\circ}$ respectively,then the ratio of their number of turns is

The time period of a freely suspended magnet is $2 \ s$. If it is broken in length into two equal parts and one part is suspended in the same way,then its time period will be.....$s$.