physics/Chem final prep (2 Viewers)

weirdguy99

Member
Joined
Mar 17, 2009
Messages
171
Location
Sydney, Australia
Gender
Male
HSC
N/A

HyperComplexxx

ლ(ಠ_ಠ ლ)
Joined
Jan 12, 2011
Messages
460
Location
behind you
Gender
Undisclosed
HSC
2011
http://www.youtube.com/watch?v=6ATppRa7aIc

conclusive evidence. this just fucked me so hard what do we talk about in the exam :S
Someone explain the physics behind this :(
Is it because of the meissner effect, the mfield of magnet cannot penetrate the superconductor thus causing it to repel?
But since it causes it to move up, surface of conductor experiences a change in flux and eddy currents are induced on surface of the superconductor such that it opposes the upward movement of the magnet(due to Lenz's law) by making a mfield to direct it back down
thus the magnet should not be levitating?
O_O wut
 

NubMuncher

Member
Joined
Jan 10, 2011
Messages
129
Gender
Male
HSC
2011
Someone explain the physics behind this :(
Is it because of the meissner effect, the mfield of magnet cannot penetrate the superconductor thus causing it to repel?
But since it causes it to move up, surface of conductor experiences a change in flux and eddy currents are induced on surface of the superconductor such that it opposes the upward movement of the magnet(due to Lenz's law) by making a mfield to direct it back down
thus the magnet should not be levitating?
O_O wut
Mindfuck.
 

weirdguy99

Member
Joined
Mar 17, 2009
Messages
171
Location
Sydney, Australia
Gender
Male
HSC
N/A
Someone explain the physics behind this :(
A superconductor below its Tc tries to prevent its internal magnetic flux from changing. So a magnetic field from a permanent magnet is excluded because a current is induced in the superconductor. This creates a force that holds the magnet in position. The magnet does not slide off the superconductor due to quantum pinning, or something like that.

Think about it this way: if you had a magnet that began to levitate from the surface of a superconductor that has transitioned to below its Tc, there would be a change in magnetic flux. Thus, the superconductor should have a current induced that pulls that magnet back towards itself, and the levitation would not happen. That's why Lenz's Law is a weak argument.
 
Last edited:

Users Who Are Viewing This Thread (Users: 0, Guests: 2)

Top