The net magnetic flux through any closed surface is:
1. negative
2. zero
3. positive
4. infinity

Figure shows the graph for magnetic hysteresis for a ferromagnetic materail. From the graph, magnetic retentivity for the material is-

1. 2.5 T

2. 1.2 T

3. 1 T

4. 4 T

A domain in ferromagnetic iron is in the form of a cube of side length \(1\) µm. The maximum possible dipole moment is:
[The molecular mass of iron is \(55\) g/mole and its density is \(7.9\) g/cm³. Assume that each iron atom has a dipole moment of \(9.27\times 10^{-24}\) Am²]
1. \(8.0\times10^{-13}\) Am²
2. \(8.0\times10^{-12}\) Am²
3. \(7.0\times10^{-13}\) Am²
4. \(7.0\times10^{-12}\) Am²

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 magnetization, \(M\) is:
1. \(8\times10^{5}~\text{A/m}\)
2. \(6\times10^{5}~\text{A/m}\)
3. \(6.5\times10^{5}~\text{A/m}\)
4. \(8.9\times10^{5}~\text{A/m}\)$\mathrm{}$

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 magnetising field \(B\) is:
1. \(10~\text{T}\) 
2. \(1~\text{T}\)
3. \(0.1~\text{T}\)
4. \(2~\text{T}\)

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 \(2\) A. If the number of turns is \(1000\) per metre, the magnetic field intensity \(H\) is:
1. \(2\times10^2\) A/m
2. \(2\times10^3\) A/m
3. \(2\) A/m
4. \(20\) A/m

In the magnetic meridian of a certain place, the horizontal component of the earth’s magnetic field is \(0.26~\text{G}\) and the dip angle is \(60^{\circ}\). The magnetic field of the earth at this location is:
1. \(0.25~\text{G}\)
2. \(0.20~\text{G}\)
3. \(0.35~\text{G}\)
4. \(0.52~\text{G}\)