Electromagnet won't work

  • #1
13
10
In my adventures through my attempt at a home laboratory i decided i would try to play with electricity a bit more.

I took an iron cylinder 1 inch diameter 6 inch length and wrapped about 4 meters of 1mm copper wire around it with a small length hanging off each side.

ImageUploadedByPhysics Forums1464331677.588642.jpg


To my understanding when i touch each side to a power source the result would be the magnetized iron, this was not the case. What did i do wrong?
 
  • Like
Likes Delta2

Answers and Replies

  • #2
DrClaude
Mentor
7,554
3,894
Is the copper wire insulated?
 
  • Like
Likes Delta2
  • #4
13
10
I got the copper wire from an old T.V. Where it was used in an inductor
 
  • #5
DrClaude
Mentor
7,554
3,894
No its not
There you go, you just built a big, straight wire. :smile:

The make an electromagnet, the current has to flow in a spiral around the core. You need insulated wire for that.

I got the copper wire from an old T.V. Where it was used in an inductor
If it was used in an inductor, then it should be insulated. It is possible that the insulation is broken (or melted), making short circuits.
 
  • #6
13
10
Ok i get it so i could say wrap the wire in electrical tape and then coil it and it should work
 
  • #7
jtbell
Mentor
15,735
3,892
If you still use non-insulated wire, make sure the individual turns don't touch each other.
 
  • Like
Likes Delta2
  • #8
DrClaude
Mentor
7,554
3,894
If you still use non-insulated wire, make sure the individual turns don't touch each other.
You need also to put some tape around the iron core to isolate it.
 
  • #9
sophiecentaur
Science Advisor
Gold Member
2020 Award
25,514
5,025
If it was used in an inductor then it must be ok for the job. There must either be an open circuit (is there any way for you to know current is actually flowing?) or a flat battery or a short between the ends of the coil.
With the amount of current that cell could probably supply, you could expect to see small sparks when you brush one of the contacts with one end of the wire.
 
  • #10
sophiecentaur
Science Advisor
Gold Member
2020 Award
25,514
5,025
Thinking about this some more I guess that you just cut the wire and didn't strip the clear laquer insulation from the ends and there is no electrical contact. Try scraping gently with a knife or with emery paper. Alternatively, applying a hot soldering iron with solder may well dissolve the laquer and give it good 'tinned' ends for a good contact. I am sure that will sort out your prob.
 
  • #11
davenn
Science Advisor
Gold Member
9,444
8,347
Is the copper wire insulated?
No its not
I got the copper wire from an old T.V. Where it was used in an inductor
well actually if it came from a coil in an old TV ... it WILL be insulated, else it wouldn't have worked for that coil

What you haven't done is scrape the enamel insulation of the ends of the wire
so use a razor blade, craft knife etc and scrape the almost clear enamel insulation of around an inch off each end
THEN it will have proper connection to the battery


cheers
Dave

PS .... I didn't read sophie's post fully .... in full agreement
 
  • #12
13
10
It works!! Thank you all
 
  • Like
Likes davenn
  • #13
davenn
Science Advisor
Gold Member
9,444
8,347
It works!! Thank you all
well done :smile:

scraping the ends of the wire did the trick, I assume ?


cheers
Dave
 
  • #14
sophiecentaur
Science Advisor
Gold Member
2020 Award
25,514
5,025
It really is unfair that they use so much 'gold' coloured laquer. Many other colours are available and everyone would spot a red or purple wire isn't plain copper.
 
  • Like
Likes davenn
  • #15
davenn
Science Advisor
Gold Member
9,444
8,347
It really is unfair that they use so much 'gold' coloured laquer. Many other colours are available and everyone would spot a red or purple wire isn't plain copper.
so true
... a nice trap for young players :wink:
 
  • Like
Likes Drakkith and sophiecentaur

Related Threads on Electromagnet won't work

  • Last Post
Replies
15
Views
6K
  • Last Post
Replies
4
Views
689
  • Last Post
Replies
12
Views
4K
Replies
2
Views
2K
Replies
1
Views
458
Replies
228
Views
16K
Replies
4
Views
10K
Replies
7
Views
14K
Top