MH's ideal coil and voltage question

[tinman]

The magnet slowing through a copper pipe is a demonstration of Lenz Law due to the fact that copper can be diamagnetic.  Electrons move at the speed of light...you can limit the number of them moving through a circuit but not slow them down.

Bill

No
It's because the shorted single turn copper coil is producing a magnetic field that apposes that which created it.


Brad

[Magneticitist]

yes, with inertia supplied by gravity.. in this case metaphorically, the ideal voltage/infinite current.
without a time constant, we can say this magnet is falling forever and ever and the pipe is an infinite length. (edit, infinite in both directions... with no 'starting point'.. so how is it moving?) Since we have no relative way of knowing if it's moving other than counting the seconds and
using some constitutive equation to solve for current, we are left to assume it's actually moving
based upon the equation and the implication that it's moving because it is being acted upon by
a force. it is, however as I have thought, more complicated than newtonian physics because we
are dealing with a kind of special relativity that we still do not understand the full nature of despite
the amazing things that engineers are capable of doing as this time. R seems like it can mathematically be represented in nature in a variety of ways. Excluding R from all
of eternity and assuming our understanding of Inductance would remain absolute doesn't
seem like something we can prove.

[Pirate88179]

No
It's because the shorted single turn copper coil is producing a magnetic field that apposes that which created it.


Brad

MIT video demonstrating Lenz Law: https://www.youtube.com/watch?v=N7tIi71-AjA

Lenz Law:

"If an induced current flows, its direction is always such that it will oppose the change which produced it." 

You are basically saying the same thing...except for the diamagnetic business.

Bill

[Magneticitist]

MIT video demonstrating Lenz Law: https://www.youtube.com/watch?v=N7tIi71-AjA

Lenz Law:

"If an induced current flows, its direction is always such that it will oppose the change which produced it." 

You are basically saying the same thing...except for the diamagnetic business.

Bill

lol basically, I have no doubt both of you understand Lenz Law. The term Diamagnetic
can be confusing though and I'm not even sure as to whether that's a 'proper' way to
say it although I perfectly understand what you mean because the copper essentially
does become 'diamagnetic' as far as I can tell. seems like the same explanation.
However I also thought diamagnetic materials referred more to materials that naturally
exhibit a strong diamagnetism, much more so than what may be found in normal conductors like
copper. For example Bismuth. still, confusing.

[Pirate88179]

lol basically, I have no doubt both of you understand Lenz Law. The term Diamagnetic
can be confusing though and I'm not even sure as to whether that's a 'proper' way to
say it although I perfectly understand what you mean because the copper essentially
does become 'diamagnetic' as far as I can tell. seems like the same explanation.
However I also thought diamagnetic materials referred more to materials that naturally
exhibit a strong diamagnetism, much more so than what may be found in normal conductors like
copper. For example Bismuth. still, confusing.

Aluminum, another good conductor, is also diamagnetic.  I have seen videos of a magnet slowly sliding down an Al plate.  Is Bismuth diamagnetic or paramagnetic? I can't remember...it has been a while.

Bill

PS  Here is just one of the aluminum vids: https://www.youtube.com/watch?v=-7IzlnFH7ww