The magnetic moment of a diamagnetic atom is:

1. 1

2. between zero and one

3. equal to zero

4. much greater than one

Two identical bar magnets are fixed with their centres at a distance d apart. A stationary charge Q is placed at P in between the gap of the two magnets at a distance D from the centre O as shown in the figure:

The force on the charge Q is in:
1. direction along OP
2. direction along PQ
3. direction perpendicular to the plane of paper
4. zero

A short bar magnet of magnet moment \(0.4\) ${\mathrm{JT}}^{-1}$ is placed in a uniform magnetic field of \(0.16\) $\mathrm{T}$. The magnet is in stable equilibrium when the potential energy is:
1. \(0.064\) J
2. \(-0.064\) J
3. zero
4.\(-0.082\) J

A magnetic needle suspended parallel to a magnetic field requires \(\sqrt{3}~\text{J}\) of work to turn it through $\mathrm{}$\(60^\circ\). The torque needed to maintain the needle in this position will be:
1. \(3\) N-m
2. \(\sqrt{3} \) N-m
3. \(\frac32\) N-m
4. \(2\sqrt{3}\) N-m

For protecting a magnetic needle, it should be placed:

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. \(\mu_d= 0 ~\text{and}~\mu_p \ne0\)

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

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. \(T_2 = \infty\)

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