For protecting a magnetic needle, it should be placed:

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

1.  moving it towards the south pole
2.  moving it towards the north pole
3.  moving it towards the equator
4.  anyone of them

Among which of the following the magnetic susceptibility does not depend on the temperature:
1. Diamagnetism 
2. Paramagnetism
3. Ferromagnetism
4. Ferrite

Two bar magnets having the same geometry with magnetic moments \(M\) and \(2M\) are firstly placed in such a way that if their similar poles are on the same side then their time period of oscillation is \(T_1\). Now if the polarity of one of the magnets is reversed then the time period of oscillation is \(T_2\). The relation between \(T_1\) & \(T_2\) is:
1. \(T_1<T_2\)
2. \(T_1=T_2\)
3. \(T_1>T_2\)
4. \(T_2 = \infty\)

Diamagnetic material in a magnetic field moves:

If the magnetic dipole moment of an atom of diamagnetic material, paramagnetic material and ferromagnetic material are denoted by \(\mu_d,~\mu_p,~\text{and}~\mu_f\) respectively, then:
1. \(\mu_p= 0 ~\text{and}~\mu_f \ne0\)
2. \(\mu_d\neq 0 ~\text{and}~\mu_p=0\)
3. \(\mu_d\ne 0 ~\text{and}~\mu_f \ne0\)
4. \(\mu_d= 0 ~\text{and}~\mu_p \ne0\)