Is copper a superconductor? (1 Viewer)

[psychopath]

for the copper block and bar magnet question .. is copper a super conductor?? did you all write the meissner effect for when ti's cooled to -50 degrees?

cos i didnt .. i didnt think copper was a super conductor .. and so i said that the magnet falls at a much slower rate but still falls ..

 

[angmor]

thats what i thought....a lower temperature = higher resistivity doesnt it? so the induced currents dont flow as well.....were we meant to know that copper is a supoerconductor????? i dont think any superconductor has that high a critical temperature of -50 anyway

 

[psychopath]

that's only in semiconductors .. but in conductors .. i.e. metals .. as temperature lowers .. vibrations int he lattice stop .. and so the resistance decreases .. it was one of the multiple choice questions ..

 

[SL33pY]

lower temp means LOWER resistance due to the fact that there are less electron vibrations in the lattice... am i right or wrong here?
i get the part about "is copper a superconductor?", i just went with the flow... the previous question was on super conductors.... low temps are required for superconductivity to be acheived.....
but arghhh i was confused like you on whether copper became a superconducter at -50....
meh hopefully i chose the correct way to answer this q

 

[mr coolerer]

I dont think Cu becomes a super conductor at -50 deg C, at -50 kelven would be closer to its critical frequency.

But i said that the magnet would take a greater amount of time to come to rest (land on the Cu brick) due to increased induced current.

 

[angmor]

lol do u think ill get any maks? i wrote that the electrical resistance becomes higher, but i did write that it would take a great amount of time....or is that contradicting myself?

 

[bboyelement]

no its not but i does lose resistant when its at a low temperature

 

[SL33pY]

lol do u think ill get any maks? i wrote that the electrical resistance becomes higher, but i did write that it would take a great amount of time....or is that contradicting myself?

contradiction = zero mista chin clearly stated that in the marking of our trials...

 

[Larryman]

I dont think Cu becomes a super conductor at -50 deg C, at -50 kelven would be closer to its critical frequency.

But i said that the magnet would take a greater amount of time to come to rest (land on the Cu brick) due to increased induced current.

uhhh bud, there isnt such a temperature as -50 K, 0K is the minimal temperature theoretically possible. but if you didnt state that you should be fine

to be safe put the inclusion of the meissner effect within your answer and you should get full marks, even if predictions are made denying levitation, which you should of done

 

[helper]

No and Meissner effect is wrong as the highest critical temp is about -135 celcius

Copper is not a superconductor at -50
http://hypertextbook.com/physics/modern/superconductivity/

 

[charismo]

I dont think Cu becomes a super conductor at -50 deg C, at -50 kelven would be closer to its critical frequency.

But i said that the magnet would take a greater amount of time to come to rest (land on the Cu brick) due to increased induced current.

dude think about what you just said.. what the hell is -50 degrees kelvin??
but in other news.. i think the correct answer would've described the fact that at reduced temps, there are fewer lattice vibrations, therefore impedence to electron flow is minimised and thus magnetic field produced is stronger.. but me being the idiot i am instead discussed that copper behaves as a super conductor at -50 degrees C.. its ciritcal temp is much lower

 

[angmor]

i think that question was kinda like a trick question - i dunno for me it was coz im so conditioned to thinking in terms of semiconductors so i thought it the other way around...oh well

 

[sinist4]

i think that question was kinda like a trick question - i dunno for me it was coz im so conditioned to thinking in terms of semiconductors so i thought it the other way around...oh well

hey... i unno, buti just basically said it would fall slower than the first... the magnet would kinda 'hover' down slowly until it hits the block :S

hahaha thats wat i did ... plz tell me if that is wrong thanxx >

 

[yaseng1988]

COPPER IS NEVER A SUPERCONDUCTOR.
I olny know 1 superconductor: YBCO
Yttrium Barium Copper Oxide.....

The rest?? who cares??

 

[hamzah]

yeah interestingly enough, copper (along with silver) are one of the few metals that never make superconductors (even at .0000000001 K). Fact of the Day for you folks.

 

[*yooneek*]

oh fudge lol
i was so debating over what to write cause i didnt really know if copper was a superconductor...the temp did seem a lil high... which was a clue i guess...
but ahhh well... i stuffed it and wrote the meissner effect would be observed

 

[*yooneek*]

yeah interestingly enough, copper (along with silver) are one of the few metals that never make superconductors (even at .0000000001 K). Fact of the Day for you folks.

i wish i knew that before the exam

 

[kannonland]

The question did say PREDICT so if you say it may be super conducting and then say the magnet will float if it is super conducting?

 

[hamzah]

nah its totally wrong, they expect you to know that no such superconductor exists at -50 C. there testing if you know resistance drops with temp, due to less latice vibrations, and that the magentic field produced by the eddy current is proportional the current ( B proportional I).

 

[ze.outlaw]

In that question I felt like it was a bit of a trick too, but as it was only a 2 marker it didn't seem like it was too hard to score full marks. I stated that the copper doesn't exhibit superconducting properties at -50C so the magnet would not levitate, but it would come to rest even more gently, due to decreased lattice vibrations in the copper at lower temperatures resulting in larger induced currents and so larger associated magnetic fields to repel the motion of the bar magnet.
Concurrence?