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
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 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. \(8.9\times10^{5}~\text{A/m}\)
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. \(0.52~\text{G}\)
The earth’s magnetic field at the equator is approximately 0.4 G. The earth’s dipole moment is:
(Radius of earth, \(R_{E}=6.4\times10^{6} \) m)
1. \(1.05\times10^{23}\) A-m2
2. \(8.0\times10^{22}\) A-m2
3. \(4.5\times10^{23}\) A-m2
4. \(2.10\times10^{23}\) A-m2
Which one of the following is correct?
1. | The magnetic field lines also represent the lines of force on a moving charged particle at every point. |
2. | Magnetic field lines can be entirely confined within the core of a toroid, but not within a straight solenoid. |
3. | A bar magnet exerts a torque on itself due to its own field. |
4. | Magnetic field arises due to stationary charges. |
Which of the following is the correct representation of magnetic field lines?
1. (g), (c)
2. (d), (f)
3. (a), (b)
4. (c), (e)
The figure shows a small magnetized needle P placed at a point O. The arrow shows the direction of its magnetic moment. The other arrows show different positions (and orientations of the magnetic moment) of another identical magnetized needle Q. Then:
1. | In configuration, the system is not in equilibrium. |
2. | In configuration, the system is unstable. |
3. | In configuration, the system is stable. |
4. | configuration corresponds to the lowest potential energy among all the configurations shown. |