Tossup

David Griffiths claims that there are really two laws of this process and that only relativity explains the equivalence between a central quantity and its “motional” form. In a common demonstration of this process, a magnet dropped through a copper tube falls unexpectedly (10[1])slowly. (10[1])This process is governed by the equation “del cross E equals minus dB/dt,” which implies that the negative time derivative of magnetic flux equals the emf (10[1])(“E-M-F”). This process creates eddy currents that rapidly heat metal in a namesake type of cooktop. (-5[1])Lenz’s Law explains the negative sign in Faraday’s law of this process. For 10 points, name this process in which a changing magnetic field creates an electric field. ■END■ (10[1])

ANSWER: electromagnetic induction [accept Faraday’s law of induction; prompt on eddy currents before “eddy” is read by asking, “what process causes them?”]
<Editors, Physics>
= Average correct buzz position

Back to tossups

Buzzes


Summary

TournamentEditionTUHConv. %Neg %Average Buzz
UK (North)UK5100%20%72.80
UK (South)UK7100%14%66.86
Northern CaliforniaUS4100%25%66.75
Southern CaliforniaUS786%57%73.00
Eastern Canada (1)US5100%60%94.20
Eastern Canada (2)US989%44%92.13
FloridaUS475%50%94.67
Great LakesUS1292%17%70.64
Lower Mid-AtlanticUS956%44%85.60
Upper Mid-AtlanticUS10100%0%72.60
Upper Mid-AtlanticUS250%50%74.00
MidwestUS9100%11%70.78
NorthUS4100%50%88.25
NortheastUS11100%9%75.64
PacificUS8100%13%69.63
SoutheastUS1385%8%72.18
Upstate NYUS6100%50%83.50