Q. No.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. \(20~\text{A/m}\)
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 \(2~\text{A}\). 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 domain in ferromagnetic iron is in the form of a cube of side length \(1~\mu\text m.\) The maximum possible dipole moment is:
[The molecular mass of iron is \(55~\text{g/mole}\) and its density is \(7.9~\text{g/cm}^3.\) Assume that each iron atom has a dipole moment of \(9.27\times 10^{-24}~\text{Am}^2\)]
1. \(8.0\times10^{-13}~\text{Am}^2\)
2. \(8.0\times10^{-12}~\text{Am}^2\)
3. \(7.0\times10^{-13}~\text{Am}^2\)
4. \(7.0\times10^{-12}~\text{Am}^2\)
A domain in ferromagnetic iron is in the form of a cube of side length \(1~\mu \text{m}\). The magnetisation of the domain is:
(The molecular mass of iron is \(55~\text{g/mole}\) and its density is \(7.9~\text{g/cm}^3\) . Assume that each iron atom has a dipole moment of \(9.27\times 10^{-24}~\text{Am}^2\))
1. \(9.0 \times 10^5~\text{Am}^{-1}\)
2. \(8.0 \times 10^5~\text{Am}^{-1}\)
3. \(11 \times 10^5~\text{Am}^{-1}\)
4. \(3.0 \times 10^5~\text{Am}^{-1}\)
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. | The 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. | The 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 \(P Q_1\) and \(P Q_2\) configuration, the system is not in equilibrium. |
| 2. | In \(P Q_3 \) and \(P Q_6\) configuration, the system is unstable. |
| 3. | In \(P Q_5\) and \(P Q_4\) configuration, the system is stable. |
| 4. | \(P Q_5\) configuration corresponds to the lowest potential energy among all the configurations shown. |
The ratio of the magnitudes of the equatorial and axial fields due to a bar magnet of length \(5.0~\text{cm}\) at a distance of \(50~\text{cm}\) from its mid-point is:
(given, the magnetic moment of the bar magnet is \(0.40~\text{Am}^{2}\))
1. \(\dfrac{1}{2}\)
2. \(2\)
3. \(1\)
4. \(\dfrac{3}{2}\)
A solenoid of cross-sectional area \(2\times 10^{-4}~\text{m}^2\) and \(1000\) turns placed with its axis at \(30^\circ\) with an external field of \(800~\text{G}\) experiences a torque of \(0.016~\text{Nm}.\) The current flowing through the solenoid is:
1. \(2~\text{A}\)
2. \(4~\text{A}\)
3. \(1~\text{A}\)
4. \(5~\text{A}\)
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