A tangent galvanometer has a coil of $25$ $turns$ and radius of $15 \,cm.$ The horizontal component of the earth’s magnetic field is  $3 × 10^{-5}$ $T$. The current required to produce a deflection of $45^o$ in it, is.....$A$

Two short magnets having magnetic moments in the ratio $27 : 8,$  when placed on opposite sides of a deflection magnetometer, produce no deflection. If the distance of the weaker magnet is $0.12$ $m$ from the centre of deflection magnetometer, the distance of the stronger magnet from the centre is.......$m$

The time period of a vibration magnetometer is $T_0$. Its magnet is replaced by another magnet whose moment of inertia is $3$ $times$ and magnetic moment is $1/3$ of the initial magnet. The time period now will be

The period of oscillation of a magnet in vibration magnetometer is $2 \,sec$. The period of oscillation of a magnet whose magnetic moment is four times that of the first magnet is...$sec$

Two tangent galvanometers having coils of the same radius are connected in series. A current flowing in them produces deflections of $60° $ and $45°$  respectively. The ratio of the number of turns in the coils is

Two different magnets are tied together and allowed to vibrate in a horizontal plane. When their like poles are joined, time period of oscillation is $5 \,s$ and with unlike poles joined, time period of oscillation is $15 \,s$. The ratio of their magnetic moments is