A short magnetic dipole of a magnetic dipole moment \({M}_{0} \hat{i}\) is placed at the origin. The Magnetic field intensity at a point with a position vector \(\alpha \hat{j}+\beta\hat{k}\) is:
1. | \(-\dfrac{\mu_{0}{M}_{0}}{4 \pi\left(\alpha^{2}+\beta^{2}\right)^{3 / 2}}\hat{i}\) |
2. | \(\dfrac{\mu_{0}{M}_{0}}{2\pi\left(\alpha^{2}+\beta^{2}\right)^{3 / 2}}\hat{i}\) |
3. | \(\dfrac{\mu_{0}{M}_{0}}{4 \pi\left(\alpha^{2}+\beta^{2}\right)^{3 / 2}}\hat{i}\) |
4. | Zero |
1. | \(6 \times 10^{-4}\) T | 2. | \(1.5 \times 10^{-4}\) T |
3. | \(3 \sqrt2 \times 10^{-4}\) T | 4. | \({\dfrac 3 {\sqrt 2}}\times 10^{-4}\) T |
1. | all the domains grow in size. |
2. | all the domains shrink in size. |
3. | some domains grow in size, others shrink. |
4. | domains rotate in the magnetic field. |
1. | \(0.75~\text{A}\) | 2. | \(75~\text{A}\) |
3. | \(1.33~\text{A}\) | 4. | \(133~\text{A}\) |
1. | \(B^{-3}\) | 2. | \(B^{-2}\) |
3. | \(B^{-1/2}\) | 4. | \(B^{-1/3}\) |
1. | attractive. |
2. | repulsive. |
3. | zero. |
4. | any of the above depending on the external field \(B\) and the sample separation. |
1. | \(E_B\cdot\tau_B\) | 2. | \(\dfrac{E_B}{\tau_B}\) |
3. | \(E_B^2+\tau_B^2\) | 4. | \(E_B^2-\tau_B^2\) |
1. | \(\dfrac{r_1}{r_2}=\dfrac{P_1}{P_2}\) |
2. | \(\left(\dfrac{r_1}{r_2}\right)^2=\dfrac{P_1}{P_2} \) |
3. | \(\left(\dfrac{r_1}{r_2}\right)^3=\dfrac{P_1}{P_2} \) |
4. | none of the above is true. |
1. | increases |
2. | decreases |
3. | remains unchanged |
4. | decreases first and then increases |