The frequency of oscillation of a small magnet in a magnetic field of induction $B$ is $n$. If the frequency of oscillations of the same magnet in a field of induction $X$ falls to $n/3$, the value of $X$ is

Twists of suspension fibre should be removed in a vibration magnetometer so that:

$A$ short magnet oscillates with a time period $0.1 \, s$ at a place where the horizontal magnetic field is $24 \, \mu T$. $A$ downward current of $18 \, A$ is established in a vertical wire kept at a distance of $20 \, cm$ east of the magnet. The new time period of oscillations of the magnet is (in $s$)

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:

When a freely suspended magnet is heated,its magnetic moment decreases by $19\%$. What is the percentage change in its time period?

$A$ bar magnet is oscillating in the earth's magnetic field with a time period $T$. If a similar magnet with the same mass and volume has a magnetic dipole moment which is $9$ times that of this magnet,then its time period will be . . . . . . .