A ferromagnetic material is placed in an external magnetic field. The magnetic domains:
1. | must increase in size. |
2. | must decrease in size. |
3. | may increase or decrease in size. |
4. | disappear. |
Due to a small magnet, the intensity at a distance \(x\) in the end-on position is \(9~\text{gauss}\). What will be the intensity at a distance \(\frac{x}{2}\) on equatorial position?
1. \(9~\text{gauss}\)
2. \(4~\text{gauss}\)
3. \(36~\text{gauss}\)
4. \(4.5~\text{gauss}\)
The magnetic moment of a bar magnet of length \(L\) and area of cross-section \(A\) is \(M\). If the magnet is cut into four identical parts each of length \(L\) and area of cross-section \(\frac{A}{4}\), then magnetic moment of each part is:
1. | \(\frac{M}{4}\) | 2. | \(\frac{M}{2}\) |
3. | \(M\) | 4. | \(4M\) |
The possible value of magnetic susceptibility of a diamagnetic material can be:
1. -2.45
2. 0.75
3. -0.5
4. 1.67
The bar magnet \(A\) of magnetic moment \(M_A\) is found to oscillate at a frequency twice that of magnet \(B\) of magnetic moment \(M_B\) and the same moment of inertia when placed in a vibration magnetometer. We may say that:
1. \(M_B=8M_A\)
2. \(M_A= 4M_B\)
3. \(M_A=8M_B\)
4. \(M_A=2M_B\)
When a magnetic material is subjected to a very small magnetising force \(H,\) the intensity of magnetisation is proportional to:
1. | \(\frac{1}{\sqrt{H}} \) | 2. | \(\sqrt{H} \) |
3. | \(H \) | 4. | \(H^2\) |
The magnetization of a piece of iron or steel:
1. | depends on the strength of the magnetizing field. |
2. | depends on external conditions such as temperature. |
3. | cannot be done beyond the saturation point. |
4. | all of these. |
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)
1. | positive. |
2. | negative. |
3. | positive or negative. |
4. | zero. |
Choose the correct statement regarding magnetism.
1. | Paramagnetic sample displays greater magnetization when cooled. |
2. | Diamagnetism is almost independent of temperature. |
3. | Ferromagnetic substances show hysteresis. |
4. | All of these. |
S.I. unit of intensity of magnetization is:
1. | Ampere-metre | 2. | Ampere-metre2 |
3. | Ampere/metre | 4. | Ampere/metre2 |