The correct direction of the magnetic field in the given figures is shown by:
1. | 2. | ||
3. | 4. |
Assertion (A): | Gauss's law for magnetism states that the net magnetic flux through any closed surface is zero. |
Reason (R): | The magnetic monopoles do not exist. North and South poles occur in pairs, allowing vanishing net magnetic flux through the surface. |
1. | (A) is True but (R) is False. |
2. | (A) is False but (R) is True. |
3. | Both (A) and (R) are True and (R) is the correct explanation of (A). |
4. | Both (A) and (R) are True but (R) is not the correct explanation of (A). |
Statement I: | The magnetic field of a circular loop at very far away point on the axial line varies with distance as like that of a magnetic dipole. |
Statement II: | The magnetic field due to magnetic dipole varies inversely with the square of the distance from the centre on the axial line. |
1. | Statement I is correct and Statement II is incorrect. |
2. | Statement I is incorrect and Statement II is correct. |
3. | Both Statement I and Statement II are correct. |
4. | Both Statement I and Statement II are incorrect. |
Diamagnetic material in a magnetic field moves:
1. | from stronger to the weaker parts of the field |
2. | from weaker to the stronger parts of the field |
3. | perpendicular to the field |
4. | in none of the above directions |
According to Curie's law, the magnetic susceptibility of a substance at an absolute temperature T is proportional to:
1. 1/T
2. T
3. 1/T2
4. T2
If the magnetic dipole moment of an atom of diamagnetic material, paramagnetic material and ferromagnetic material are denoted by \(\mu_d,~\mu_p,~\text{and}~\mu_f\) respectively, then:
1. \(\mu_p= 0 ~\text{and}~\mu_f \ne0\)
2. \(\mu_d\neq 0 ~\text{and}~\mu_p=0\)
3. \(\mu_d\ne 0 ~\text{and}~\mu_f \ne0\)
4. \(\mu_d= 0 ~\text{and}~\mu_p \ne0\)
For protecting a magnetic needle, it should be placed:
1. | In an iron box. |
2. | In a wooden box. |
3. | In a metallic box. |
4. | None of these. |
1. | 2. | ||
3. | 4. |
Figure shows two small identical magnetic dipoles \(a\) and \(b\) of magnetic moments \(M\) each, placed at a separation \(2d\), with their axes perpendicular to each other. The magnetic field at the point \(P\) midway between the dipoles is:
1. | \(\dfrac{2 \mu_{0} M}{4 \pi d^{3}}\) | 2. | \(\dfrac{\mu_{0} M}{4 \pi d^{3}}\) |
3. | zero | 4. | \(\dfrac{\sqrt{5}\mu_{0} M}{4\pi d^{3}}\) |