Question
The derivative of this quantity with respect to the four-potential gives the four-current density. For 10 points each:
[10h] Name this quantity which, for a free electromagnetic field, is equal to [read slowly] negative one fourth times the contraction of the field strength tensor with itself.
ANSWER: electromagnetic Lagrangian
[10m] Applying the Euler-Lagrange equations to the electromagnetic Lagrangian yields this equation which states the curl of the electric field equals the negative time derivative of the magnetic field.
ANSWER: Faraday’s law of induction [accept Maxwell-Faraday law]
[10e] The vanishing differential of the field strength tensor implies the local conservation of this quantity. The current represents the rate that this quantity flows through a given surface.
ANSWER: electric charge
<IC, Physics>
Summary
| 2023 ILLIAC (Cornell) | 2023-10-21 | Y | 1 | 20.00 | 100% | 100% | 0% |
| 2023 ILLIAC (Mainsite) | 2023-10-21 | Y | 1 | 10.00 | 100% | 0% | 0% |
Data
| Missouri | WUSTL | 0 | 0 | 10 | 10 |