Author |
Topic: Magnet Detection (Read 2488 times) |
|
Kozo Morimoto
Guest
|
Trying to remember my primary school physics...
I recall drawing magnetic field line between the poles and getting weaker as it gets to the middle of the magnetic rod...
So if you hold the 2 rods in a "T" shape and the rods stick, then the bottom of the "T" is the magnet. If it doesn't do anything, then the top of the "T" is the magnet.
|
|
 IP Logged |
|
|
|
Chris-Bob
Guest
|
Alternatively, balance one on the center of the other (or on a finger, if that doesn't count as an "instrument"), and spin them as a unit. If the rod that's free to pivot does (i.e. aligns itself along the earth's magnetic field as a compass), then it's the magnet.
|
|
IP Logged |
|
|
|
jim p
Guest
|
Assuming they were thin enough and that you were strong enough to break the rods in half, you could easliy determine this. Take the opposite ends of the rod you broke and push them towards eachother. If you see that they oppose eachother (as the poles N and P would) that is the magnet. If not, that is the normal iron rod.
|
|
IP Logged |
|
|
|
James Fingas
Uberpuzzler
Gender: 
Posts: 949
|
 |
Re: Magnet Detection
« Reply #3 on: Aug 30th, 2002, 12:55pm » |
 Quote  Modify
|
Jim,
Actually, that's the answer I was thinking of, but:
1) Physical shock can demagnetize magnets
2) Physical shock can spontaneously magnetize magnetic materials
So you might be left with two sort-of magnets and a lot of confusion.
|
|
IP Logged |
Doc, I'm addicted to advice! What should I do?
|
|
|
shivbits1
Newbie
Posts: 3
|
|
Re: Magnet Detection
« Reply #4 on: Sep 24th, 2002, 1:36pm » |
Quote Modify
|
the rods will stick in T shape no matter what.
the field is weak in the middle of the magnet but a field still exists.
So in T shape, even if the top of the T is the magnet, they will still stick.
on Aug 2nd, 2002, 6:25pm, Kozo Morimoto wrote:Trying to remember my primary school physics...
I recall drawing magnetic field line between the poles and getting weaker as it gets to the middle of the magnetic rod...
So if you hold the 2 rods in a "T" shape and the rods stick, then the bottom of the "T" is the magnet. If it doesn't do anything, then the top of the "T" is the magnet. |
|
|
|
IP Logged |
|
|
|
shivbits1
Newbie
Posts: 3
|
|
Re: Magnet Detection
« Reply #5 on: Sep 24th, 2002, 2:49pm » |
Quote Modify
|
ok, dealing with the demagnetization due to shock,
so lets not 'hammer' the magnets.
use a nice hacksaw and finely saw of a piece of the magnet!
on Aug 30th, 2002, 12:55pm, James Fingas wrote:Jim,
Actually, that's the answer I was thinking of, but:
1) Physical shock can demagnetize magnets
2) Physical shock can spontaneously magnetize magnetic materials
So you might be left with two sort-of magnets and a lot of confusion. |
|
|
|
IP Logged |
|
|
|
Jeremiah Smith
Full Member
Beep!
Posts: 172
|
|
Re: Magnet Detection
« Reply #6 on: Sep 24th, 2002, 8:21pm » |
Quote Modify
|
on Sep 24th, 2002, 1:36pm, shivbits1 wrote:the rods will stick in T shape no matter what.
the field is weak in the middle of the magnet but a field still exists.
So in T shape, even if the top of the T is the magnet, they will still stick.
|
|
Well, you could always check to see which T is stronger.
|
|
IP Logged |
|
|
|
Kozo Morimoto
Junior Member
Posts: 114
|
|
Re: Magnet Detection
« Reply #7 on: Sep 27th, 2002, 5:15pm » |
Quote Modify
|
I remember doing experiments back in grade 1 trying to pick up iron filings and paper clips. You could not pick up iron filings at the middle of the rod magnet.
Maybe still using the T shape, but by sliding the bottom of the T side ways back and forth and see if the strength of the attration changes. If it doesn't, then you are holding the magnet, if it does change, then the top of the T is the magnet.
|
|
IP Logged |
|
|
|
BB
Guest
|
Didn't anyone ever turn a piece of metal into a magnet before? Iron has a great affinity for being able to temporarily turn into a magnet.
Rub the ends of the iron rods together for a while. Usually its best to rub in one direction like honing a knife. After a while, spin one of the magnets around. If it attracts, its just a piece of iron. If it repels, its a magnet.
|
|
IP Logged |
|
|
|
Grimbal
wu::riddles Moderator
Uberpuzzler
Gender:
Posts: 7527
|
|
Re: Magnet Detection
« Reply #9 on: Sep 5th, 2005, 1:44am » |
Quote Modify
|
on Sep 4th, 2005, 12:31pm, BB wrote:| Rub the ends of the iron rods together for a while. Usually its best to rub in one direction like honing a knife. After a while, spin one of the magnets around. If it attracts, its just a piece of iron. If it repels, its a magnet. |
|
I'm not convinced.
If you are rubbing the 2 pieces of metal, and one of them is a magnet, the other will magnetize. Assuming the magnetization is strong enough, regardless of which was the neutral iron, they will repel.
About another suggestion to saw the bar in 2, as soon as you have a little metal dust, you can tell easily which of the bars is the magnet.
|
|
IP Logged |
|
|
|
towr
wu::riddles Moderator
Uberpuzzler
Some people are average, some are just mean.
Gender:
Posts: 13730
|
|
Re: Magnet Detection
« Reply #10 on: Sep 5th, 2005, 2:53am » |
Quote Modify
|
on Sep 5th, 2005, 1:44am, Grimbal wrote:
I'm not convinced.
If you are rubbing the 2 pieces of metal, and one of them is a magnet, the other will magnetize. Assuming the magnetization is strong enough, regardless of which was the neutral iron, they will repel. |
|
Only if the entire bar of iron is magnetized, it's much more likely it will only be magnetic at one end, I think.
|
|
IP Logged |
Wikipedia, Google, Mathworld, Integer sequence DB
|
|
|
rmsgrey
Uberpuzzler
    
Gender:
Posts: 2873
|
|
Re: Magnet Detection
« Reply #11 on: Sep 5th, 2005, 6:02am » |
Quote Modify
|
on Sep 5th, 2005, 2:53am, towr wrote:
Only if the entire bar of iron is magnetized, it's much more likely it will only be magnetic at one end, I think. |
|
But iron in contact with a magnet tends to act like a magnet - anyone who's ever played with steel paperclips and a magnet will know that,aslong as you keep the chain unbroken, you can pick up a lot of paperclips - break the chain in the middle, and the portion not connected to the magnet will fall apart.
|
|
IP Logged |
|
|
|
towr
wu::riddles Moderator
Uberpuzzler
Some people are average, some are just mean.
Gender:
Posts: 13730
|
|
Re: Magnet Detection
« Reply #12 on: Sep 5th, 2005, 12:49pm » |
Quote Modify
|
on Sep 5th, 2005, 6:02am, rmsgrey wrote:
But iron in contact with a magnet tends to act like a magnet - anyone who's ever played with steel paperclips and a magnet will know that,aslong as you keep the chain unbroken, you can pick up a lot of paperclips - break the chain in the middle, and the portion not connected to the magnet will fall apart. |
|
But the chain can only go so long, even when you don't hang the chain (which would increase the force)
So i suppose it depends on the size of the bar..
|
|
IP Logged |
Wikipedia, Google, Mathworld, Integer sequence DB
|
|
|
Justin
Guest
|
on Sep 24th, 2002, 2:49pm, shivbits1 wrote:ok, dealing with the demagnetization due to shock,
so lets not 'hammer' the magnets.
use a nice hacksaw and finely saw of a piece of the magnet!
|
|
You're not allowed to use any other instruments!
|
|
IP Logged |
|
|
|
|
RIDDLES SITE
WRITE MATH!
Home 
Help 
Search 
Members 
Login 
Register
Reply
Notify of replies
Send Topic
Print
Remove