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

Two magnets $A$ and $B$ are identical in mass,length,and breadth but have different magnetic moments. In a vibration magnetometer,if the time period of $B$ is twice the time period of $A$,then the ratio of the magnetic moments $M_A/M_B$ of the magnets will be:

When $2 \ A$ current is passed through a tangent galvanometer,it gives a deflection of $30^\circ$. For $60^\circ$ deflection,the current must be........$A$.

The magnetic moments of two bar magnets of same size are in the ratio $1:2$. When they are placed one over the other with their similar poles together,their period of oscillation in a magnetic field is $3 \, s$. If one of the magnets is reversed,then the period of oscillation in the same field will be ......... $s$.

When the $N$-pole of a bar magnet points towards the geographic south and the $S$-pole points towards the geographic north,the null points are located at the:

The periodic time of a magnet in a vibration magnetometer is $T_0$. If the magnet is replaced by another magnet whose moment of inertia is three times and magnetic moment is one-third of the original magnet, then the time period of the new magnet will be: