The time period of oscillation of a magnet in a vibration magnetometer is $1.5$ seconds. The time period of oscillation of another magnet similar in size, shape and mass but having one-fourth magnetic moment than that of first magnet, oscillating at same place will be…..$sec$

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

The number of turns and radius of cross-section of the coil of a tangent galvanometer are doubled. The reduction factor $K $ will be

When $\sqrt 3 $ $ampere$ current is passed in a tangent galvanometer, there is a deflection of $ 30° $ in it. The deflection obtained when $3$ $ampere$ current is passed, is…..$^o$

A tangent galvanometer has a coil of $25$ $turns$ and a radius of $15\, cm$. The horizontal component of the earth’s magnetic field is $3\times10^{-5}\, T$. The current required to produce a deflection of $45^o$ in it is….$A$