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. |
A material when heated suddenly changes its magnetic property at a particular temperature and above this temperature, its susceptibility is found to be inversely proportional to the absolute temperature. The material may be:
1. Ferromagnetic
2. Diamagnetic
3. Paramagnetic
4. Ferromagnetic or Paramagnetic
Elements of Earth's magnetism is/are
1. Magnetic declination
2. Magnetic Inclination (or dip)
3. The horizontal component of the earth's magnetic field
4. All of these
At angle cos-1 to the magnetic meridian, the apparent dip is 60. The true dip at the place is :
1. 30
2. 45
3. 0
4. 60
As we go from the magnetic equator towards the geographic south pole, the angle of the dip will become:
1. | More and more vertically downward and perpendicular to the surface at the magnetic pole. |
2. | More and more vertically upward and perpendicular to the surface at the magnetic pole. |
3. | Less and less vertically downward and horizontal at the magnetic pole. |
4. | Less and less vertically upward and horizontal at the magnetic pole. |
Soft iron is used to manufacture electromagnets because:
1. It has a high permeability.
2. Its retentivity and coercivity are small.
3. Its retentivity and coercivity are high.
4. Both (1) & (2)
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. |
Given below are two statements:
Statement I: | \(\oint \vec{B} \cdot \overrightarrow{d s}=0\) because magnetic monopoles do not exist. |
Statement II: | \(\oint \vec{B} \cdot \overrightarrow{d s}=0\) means the magnetic field is zero. |
1. | Statement I is false but Statement II is true. |
2. | Both Statement I and Statement II are true. |
3. | Both Statement I and Statement II are false. |
4. | Statement I is true but Statement II is false |
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. |
If a bar magnet is kept on a horizontal plane with N-pole of bar magnet facing geographic N-pole and S-pole of bar magnet facing geographic S-pole, then the number of neutral points is:
1. | 0 | 2. | 1 |
3. | 2 | 4. | Infinite |