The strength of the magnetic field in which the magnet of a vibration magnetometer is oscillating is increased $4$ times its original value. The frequency of oscillation would then become

The period of oscillation of a magnet of a vibration magnetometer is $2.45 \,s$ at one place and $4.9 \,s$ at the other. The ratio of the horizontal component of earth magnetic field at the two places is .........

A certain amount of current when flowing in a properly set tangent galvanometer, produces a deflection of $ 45°.$  If the current be reduced by a factor of $\sqrt 3 $, the deflection would

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

In a vibration magnetometer, the time period of a bar magnet oscillating in horizontal component of earth's magnetic field is $2$ $sec$. When a magnet is brought near and parallel to it, the time period reduces to $1 $ $sec$. The ratio $H/F $ of the horizontal component $H$  and the field $F$ due to magnet will be

The length of a magnet is large compared to its width and breadth. The time period of its oscillation in a vibration magnetometer is $2 \,s. $ The magnet is cut along its length into three equal parts and three parts are then placed on each other with their like poles together. The time period of this combination will be