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. | \(M_A=2M_B\) |
Magnetic screening is:
1. Not possible
2. Possible using superconductors
3. Possible using the iron ring as cover
4. Both (2) & (3)
The apparent dip at a place is always greater than or equal to the value of true dip at that place. This is due to
1. An increase in the apparent value of BV
2. A decrease in the apparent value of BH
3. An increase in the apparent value of BH
4. Both (1) & (2)
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 |
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. |
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
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
A long solenoid has 1500 turns per metre and an iron core of = 1100 is kept inside it. 2A current flows in the coil of the solenoid. If the core is heated beyond curie temperature, then:
1. | The H and B fields in the solenoid reduce to zero. |
2. | The H and B fields in the solenoid remain unchanged. |
3. | The H field in the solenoid is nearly unchanged but B field decreases significantly. |
4. | The B field in the solenoid is nearly unchanged but the H field decreases significantly. |