Packet F: Bonus 17
The topology of these constructs is given by their helicity, which is the sum of their writhe and twist. For 10 points each:
[10e] Name these vector fields whose lines can be visualized using iron filings and are drawn from the north to south pole.
ANSWER: magnetic fields [accept magnetic field lines; or B-field]
[10m] For a particle in a non-uniform magnetic field, they experience a component of this quantity proportional to the gradient of B. For electrons in a uniform electric field, this quantity equals mobility times electric field.
ANSWER: drift velocity [prompt on drift; prompt on velocity; prompt on u]
[10h] Moving particles in a magnetic field also experience a drift velocity term named for and proportional to this quantity. In MHD, magnetic fields with a non-zero value of this quantity experience magnetic tension equal to this quantity times B-squared over permeability of free space.
ANSWER: curvature [accept curvature drift; prompt on kappa; reject “radius of curvature”]
<WashU A, Physics> | Packet F - Chicago C, McGill C, WashU A, Chicago B
| Heard | PPB | E % | M % | H % |
|---|---|---|---|---|
| 63 | 10.48 | 92% | 13% | 0% |
Conversion
| Team | Opponent | Part 1 | Part 2 | Part 3 | Total | Parts |
|---|---|---|---|---|---|---|
| Birmingham | Imperial B | 10 | 0 | 0 | 10 | E |
| Durham | LSE | 10 | 0 | 0 | 10 | E |
| Edinburgh A | Cambridge A | 10 | 0 | 0 | 10 | E |
| Imperial A | Bristol | 10 | 10 | 0 | 20 | EM |
| Imperial C | City St. George's | 10 | 0 | 0 | 10 | E |
| Montpellier | Southampton A | 10 | 0 | 0 | 10 | E |
| Oxford A | Cambridge B | 10 | 0 | 0 | 10 | E |
| Oxford B | Cambridge C | 10 | 0 | 0 | 10 | E |
| UCL | Edinburgh B | 10 | 0 | 0 | 10 | E |
| Warwick A | Manchester | 10 | 0 | 0 | 10 | E |
Summary
| Tournament | Edition | Match | Heard | PPB | E % | M % | H % |
|---|---|---|---|---|---|---|---|
| California (North) | Main Site | ✓ | 3 | 13.33 | 100% | 33% | 0% |
| California (South) | Main Site | ✓ | 4 | 7.50 | 75% | 0% | 0% |
| Canada | Main Site | ✓ | 7 | 8.57 | 86% | 0% | 0% |
| Florida | Main Site | ✓ | 1 | 20.00 | 100% | 100% | 0% |
| Great Lakes | Main Site | ✓ | 5 | 14.00 | 100% | 40% | 0% |
| Lower Mid-Atlantic | Main Site | ✓ | 7 | 10.00 | 100% | 0% | 0% |
| Midwest | Main Site | ✓ | 5 | 8.00 | 80% | 0% | 0% |
| Northeast | Main Site | ✓ | 3 | 13.33 | 100% | 33% | 0% |
| Overflow | Main Site | ✓ | 3 | 10.00 | 100% | 0% | 0% |
| South Central | Main Site | ✓ | 1 | 0.00 | 0% | 0% | 0% |
| Southeast | Main Site | ✓ | 5 | 10.00 | 100% | 0% | 0% |
| UK | Main Site | ✓ | 10 | 11.00 | 100% | 10% | 0% |
| Upper Mid-Atlantic | Main Site | ✓ | 7 | 11.43 | 100% | 14% | 0% |
| Upstate NY | Main Site | ✓ | 2 | 10.00 | 50% | 50% | 0% |