A magnetic dipole of dipole moment $$\overrightarrow {\bf{m}} $$ is placed in a non-uniform magnetic field $$\overrightarrow {\bf{B}} .$$ If the position vector of the dipole is $$\overrightarrow {\bf{r}} ,$$ the torque acting on the dipole about the origin is
A. $$\overrightarrow {\bf{r}} \times \left( {\overrightarrow {\bf{m}} \times \overrightarrow {\bf{B}} } \right)$$
B. $$\overrightarrow {\bf{r}} \times \overrightarrow \nabla \left( {\overrightarrow {\bf{m}} .\overrightarrow {\bf{B}} } \right)$$
C. $$\overrightarrow {\bf{m}} \times \overrightarrow {\bf{B}} $$
D. $$\overrightarrow {\bf{m}} \times \overrightarrow {\bf{B}} + \overrightarrow {\bf{r}} \times \overrightarrow \nabla \left( {\overrightarrow {\bf{m}} .\overrightarrow {\bf{B}} } \right)$$
Answer: Option B
This Question Belongs to Engineering Physics >> Electromagnetic Theory
A. $$\frac{2}{{{\mu _0}}}\left( {x{\bf{\hat i}} + y{\bf{\hat j}}} \right)$$
B. $$ - \frac{2}{{{\mu _0}}}\left( {{\bf{\hat i}} + {\bf{\hat J}}} \right)$$
C. $$ - \frac{2}{{{\mu _0}}}\left( {{\bf{\hat i}} - {\bf{\hat j}}} \right)$$
D. $$\frac{2}{{{\mu _0}}}\left( {x{\bf{\hat i}} - y{\bf{\hat j}}} \right)$$
A. 0.033 μm
B. 0.330 μm
C. 3.300 μm
D. 33.000 μm
A. $${\bf{\hat z}}k$$
B. $${\bf{\hat x}}k\sin \alpha + {\bf{\hat y}}k\cos \alpha $$
C. $${\bf{\hat x}}k\cos \alpha + {\bf{\hat y}}k\cos \alpha $$
D. $$ - {\bf{\hat z}}k$$
A. vp = vg
B. vp = $${\text{v}}_{\text{g}}^{\frac{1}{2}}$$
C. vp vg = c2
D. vg = $${\text{v}}_{\text{p}}^{\frac{1}{2}}$$
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