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3:45 AM
@Anusha would you mind sharing the source?
 
 
2 hours later…
5:26 AM
@PrateekMourya ping me if you want to pick up that question about the beam of nitrogen atoms
 
5:38 AM
Can I send math related questions here?
math room is a bit inactive
 
Yes, you can ask. Whether you'll get an answer depends on who is around. I'm not especially good at maths so I probably can't answer.
 
6:13 AM
@RishiNandhaVanchi hopefully I can help :-)
 
I'm solving this matrices problem, first line has given information.
question asks for sum of all elements in A, Im getting -5 but given answer is +5
trying to solve it without getting the rearrangement part involved (we'd get terms like a^2 - bc if we expand the A^2 equation into linear equations)
 
oh, you said all elements
yes, your A is correct. I am getting the same A.
the sum of the diagonal elements in A^2, is +5, I wonder if thats what the question was asking..
 
6:49 AM
oh
Ill check
thanks!
 
saturation when all of them have oriented and no more polarization can happen
 
And note that the BCC lattice has two iron atoms per unit cell.
 
ok
@JohnRennie But I did not get the correct answer...
Can you explain slightly
 
What answer did you get, and what is the correct answer?
 
6:56 AM
I got 784.520
Answer is 1500 to 1600
I mean anything in the range is correct
 
It looks to me as if your answer is exactly half what it should be.
 
ok
But where did I go wrong then?
 
Did you take into account that a BCC unit cell contains two iron atoms?
 
Can you tell me the values @JohnRennie ?
 
@user586228 Start with a cubic metre of iron, how many unit cells does this contain?
 
7:04 AM
$2/(0.287*10^-9) m^3$
Yes??
This is the total number of atoms
Why should I think about the number of unit cells?
@JohnRennie
 
We'll call d the cell size i.e. d = 0.287nm, then the volume of the cell is d³. Yes?
 
Yes
 
So the number of cells per cubic metre is 1/d³
And each cell contains two atoms, so the number of atoms per cubic metre is 2/d³
OK so far?
 
Yes...
 
And each atom has a magnetic moment of 2μ
So the total magnetic moment is 2μ x 2/d³
 
7:10 AM
total magnetic moment per metre cube
Yes?
 
Yes
Look at the units. They are in metres, so we need to take one cubic metre.
 
ok
Thanks a lot
 
:-)
Where did you go wrong? you obviously missed a factor of two somewhere.
 
7:13 AM
Yes I did not do 2/d^3
I straightway did 2 meu /d^3
 
BCC contains two atoms per unit cell. That's why we have the extra factor of two.
 
correct..
So basically saturation magnetization is total magnetic moment per m^3?
 
Yes
 
ok....
May I have another request@JohnRennie
 
Yes
 
7:20 AM
Can I discuss a probability problem with you in a separate chatroom
The problem is mainly with solving equations.
@JohnRennie
 
I'm not particularly good at probability calculations, but you can ask.
 
ok..
Ca you create a separate chatroom for that?
Can**
@JohnRennie
 
 
4 hours later…
11:25 AM
Let us say you have a question that has many downvotes . So do you remove that question ?. What do you do if it says you cannot remove it as others have invested time in it.
 
11:36 AM
@user102532 are you thinking of this question?
 
Yes.
@JohnRennie
 
You can't delete a question if it has an answer, so there isn't anything you can do.
 
Hmm.but what do you do in that case ?
@JohnRennie
 
But I've upvoted it so at least it's only -2 now :-)
 
Oh.Thnx a lot
i just feel bad of it really
 
11:42 AM
@user102532 there isn't anything you can do. If you persuaded ultralegend5385 to delete their answer then you could delete the question, but I would just forget it and move on.
I have some really bad answers from my early days on the site that I cannot delete because they have been accepted. These things we just have to live with.
 
@JohnRennie :0 unbelievable.
 
It happens :-)
 
@JohnRennie thnx. I feel motivated
 
:-)
 
 
5 hours later…
4:25 PM
@satan29 I'm getting 24 possibilities
right?
 
 
7 hours later…
11:53 PM
@RishiNandhaVanchi prnt.sc/wxydxk
 

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