The variation of the intensity of magnetisation (I) with respect to the magnetising field (H) in a diamagnetic substance is described by the graph

1. OD                            2. OC

3. OB                            4. OA

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. \(10^{4}~\text{A/m}\)

A uniform magnetic field, parallel to the plane of the paper existed in space initially directed from left to right. When a bar of soft iron is placed in the field parallel to it, the lines of force passing through it will be represented by:

1.		2.
3.		4.

The magnetization of a piece of iron or steel:

A solenoid has a core of material with relative permeability \(400.\) The windings of the solenoid are insulated from the core and carry a current of \(2~\text A.\) If the number of turns is \(1000\) per metre, the magnetic field intensity \(H\) is:
1. \(2\times10^2~\text{A/m}\)
2. \(2\times10^3~\text{A/m}\)
3. \(2~\text{A/m}\) 
4. \(20~\text{A/m}\)

An iron rod of susceptibility \(599\) is subjected to a magnetizing field of \(1200~\text{A m}^{-1}.\) The permeability of the material of the rod is:
\((\mu_0 = 4 \pi\times 10^{-7}~\text{T mA}^{-1})\)
1. \(8.0\times 10^{-5}~\text{T mA}^{-1}\)
2. \(2.4\pi\times 10^{-5}~\text{T mA}^{-1}\)
3. \(2.4\pi\times 10^{-7}~\text{T mA}^{-1}\)
4. \(2.4\pi\times 10^{-4}~\text{T mA}^{-1}\)