At a place, the angle of dip is 30. If the horizontal component of the earth's magnetic field is B, the total intensity is:
1.
2.
3. 2B
4. B
The magnetic moment of a magnet \((10 ~\text{cm}\times 4~\text{cm}\times1~\text{cm})\) is \(4 ~\text{Am}^2\). Its intensity of magnetisation is:
1. \(10^{3}\) A/m
2. \(10^{2}\) A/m
3. \(10^{5}\) A/m
4. \(10^{4}\) A/m
S.I. unit of intensity of magnetization is:
1. | Ampere-metre | 2. | Ampere-metre2 |
3. | Ampere/metre | 4. | Ampere/metre2 |
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. |
A compass needle which is allowed to move in a horizontal plane is taken to a geomagnetic pole. It will:
1. stay in the east-west direction only.
2. stay in any position.
3. become rigid showing no movement.
4. stay in the north-south direction only.
1. | \(9~\text{gauss}\) | 2. | \(4~\text{gauss}\) |
3. | \(36~\text{gauss}\) | 4. | \(4.5~\text{gauss}\) |
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. | \(H^2\) |
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 |