Using a bar magnet `P`, a vibration magnetometer has time period 2 sec. When a bar Q (identical to P in mass and size) is placed on top of P, the time period is unchanged. Which of the following statements is true?

For a vibration magnetometer, the time period of suspended bar magnet can be reduced by -

With a standard rectangular bar magnet of length (l), breadth (b,bltlt) and magnetic moment M, the time period of the magnet in a vibration magnetometer is 4 s. If the magnet is cut normal to its length into four equal pieces, the time period (in second) with one of the piece is

A short bar magnet having magnetic moment 4 Am^2 , placed in a vibrating magnetometer, vibrates with a time period of 8 s. Another short bar magnet having a magnetic moment 8Am^2 vibrates with a time period of 6 s. If the moment of inertia of the second magnet is 9 xx 10^(-2) kgm^2 , the moment of inertia of the first magnet is (assuming that both magnets are kept in the same uniform magnetic induction field):

A short bar magnet is oscillating in a magnetic field and its time period is 2 seconds. If another piece of brass of double meoment of inertia be placed over that magnet the time period of that combination in that field is

With a standard rectangular bar magnet the time period of a vibration magnetometer is 4 s. The bar magnet is cut parallel to its length into four equal pieces. The time period of vibration magnetometer when one piece is used (in second) (bar magnet breadth is small) is

With a standard rectangular bar magnet the time period of a vibration magnetometer is 4 s. The bar magnet is cut parallel to its length into four equal pieces. The time period of vibration magnetometer when one piece is used (in second) (bar magnet breadth is small) is