Figure shows two small identical magnetic dipoles \(a\) and \(b\) of magnetic moments \(M\) each, placed at a separation \(2d\), with their axes perpendicular to each other. The magnetic field at the point \(P\) midway between the dipoles is:

         
 

1.	\(\dfrac{2 \mu_{0} M}{4 \pi d^{3}}\)	2.	\(\dfrac{\mu_{0} M}{4 \pi d^{3}}\)
3.	zero	4.	\(\dfrac{\sqrt{5}\mu_{0} M}{4\pi d^{3}}\)

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. \(\mu_d= 0 ~\text{and}~\mu_p \ne0\)

Which of the following is the correct representation of magnetic field lines?

Choose the correct statement regarding magnetism.

A Gaussian surface is drawn enclosing the N-pole of a bar magnet. The net magnetic flux through the Gaussian surface will be:
(pole strength of N-pole is treated as positive and S-pole as negative)

The magnetization of a piece of iron or steel:

The magnetic moment of a magnet \((10 ~\text{cm}\times 4~\text{cm}\times1~\text{cm})\) is \(4 ~\text{Am}^2\). Its intensity of magnetisation is:
1. \(10^{3}~\text{A/m}\)
2. \(10^{2}~\text{A/m}\)
3. \(10^{5}~\text{A/m}\)
4. \(10^{4}~\text{A/m}\)

The material which is used to make permanent magnet has:

There are four light-weight-rod samples; A, B, C, D separately suspended by threads. A bar magnet is slowly brought near each sample and the following observations are noted:

Which one of the following is true?