ALL PHYSICS DOUBTS - POST HERE !!

[holtadit]

2nd one

I know not to doubt you, but are you sure ?   

[nid404]

I know not to doubt you, but are you sure ?   

lol...you should...nothing wrong

logically it's the 2nd one...it has to be!! lol

[Snake]

PD is measured in two places, so its the 2nd one

[haris94]

yup its the 2nd one

[Vin]

okay jus a quick conformation...

a permanent magnet can be demagnetized by wrapping a coil and passing alternating current

steel can be permanently magnetized by passing direct current

right>>?

also can somebody explain me the reason behind it too..i forgot

[Ghost Of Highbury]

Demagnetize by heating the magnet strongly enuf or past the Curie Temperature.

ALso, by placing the magnet in an alternating magnetic field which can be created by coiling it and passing an A/C current.

Passing direct current will only make it magnetized. Steel can be permanently magnetized by Stroking (Moving a magnet from one end of the item to the other repeatedly) or by Placing it in an external magnetic field.

The most common method is stroking, however there is another method which involves the magnet to be heated strongly, and allowed to be cool in a magnetic field and hammering it as it cools.

[Baladya]

Demagnetize by heating the magnet strongly enuf or past the Curie Temperature.

ALso, by placing the magnet in an alternating magnetic field which can be created by coiling it and passing an A/C current.

Passing direct current will only make it magnetized. Steel can be permanently magnetized by Stroking (Moving a magnet from one end of the item to the other repeatedly) or by Placing it in an external magnetic field.

The most common method is stroking, however there is another method which involves the magnet to be heated strongly, and allowed to be cool in a magnetic field and hammering it as it cools.

Another thing, you can also place the magnet W-E and hammer it (demagnetise). Also, the heating method is the best method for demagnetising

[Vin]

ok thnkx guys..

[Ghost Of Highbury]

Ur welcome.

[The Golden Girl =D]

Demagnetize by heating the magnet strongly enuf or past the Curie Temperature.

ALso, by placing the magnet in an alternating magnetic field which can be created by coiling it and passing an A/C current.

2.Passing direct current will only make it magnetized. Steel can be permanently magnetized by Stroking (Moving a magnet from one end of the item to the other repeatedly) or by Placing it in an external magnetic field.

The most common method is stroking, however there is another method which involves the magnet to be heated strongly, and allowed to be cool in a magnetic field and hammering it as it cools.

for no 2 does the steel have to be moved in and out or just placed in it's place and it'll simply get demagnetized? ....... can someone plz clear my doubt in this 
um 

[Ghost Of Highbury]

No need to move it, just pass an A/C current around it to demagnetize it.

[The Golden Girl =D]

No need to move it, just pass an A/C current around it to demagnetize it.

thx

[Ghost Of Highbury]

Anytime.

[$H00t!N& $t@r]

can sme1 plz help me with the igcse physics paper 6 O/N 2009, by sending the diagrams for Q3d(i) (including the further question asked in Q3d(ii) (1))   and Q4b(iii)

http://www.xtremepapers.net/CIE/Cambridge%20IGCSE/0625%20-%20Physics/0625_w09_qp_6.pdf

Thanks!

[Ghost Of Highbury]

Can u copy paste the question plz? for some reason i cant open that link? FEP too.