What is the physical interpretation of $\oint \mathbf{A} \cdot d\mathbf{l}$? 1. The current density $\mathbf{J}$ 2. The magnetic field $\mathbf{B}$ 3. The magnetic flux $\Phi_B$ 4. It's none of the above, but is something simple and concrete 5. It has no particular physical interpretation at all Note: * CORRECT ANSWER: C
## Announcements * Homework 13 * Due Wednesday Dec 6th * Last class: Friday Dec 8th * Full wrapup of everything we learned this year * Don't miss it! * Final Exam: Tuesday Dec 12th * 12:45pm-2:45pm * In this room (BPS 1415) * See mee for accomodations
## Special Colloquium ### Danny's promotion talk * Tuesday, Dec 5th * 4:10pm-5:10pm * In this room (BPS 1415)
## Magnetic Dipoles <img src="./images/magfield_dipole.png" align="center" style="width: 500px";/>
The leading term in the vector potential multipole expansion involves: $\oint d\mathbf{l}'$ What is the magnitude of this integral? 1. $R$ 2. $2\pi R$ 3. 0 4. Something entirely different/it depends! Note: * CORRECT ANSWER: C
<img src="./images/magnetic_dipole_oriented.png" align="left" style="width: 300px";/> Two magnetic dipoles $m_1$ and $m_2$ (equal in magnitude) are oriented in three different ways. Which ones can produce a dipole field at large distances? 1. None of these 2. All three 3. 1 only 4. 1 and 2 only 5. 1 and 3 only Note: * CORRECT ANSWER: E