The h Bar

General chat for Physics SE (physics.stackexchange.com). For M...
Jun 30 11:17
A book claims the following statement, "if in a region of space magnetic field is unidirectional, then at every point of space it must be uniform in magnitude also". Is this true? I feel like I'm missing something, because if we consider a current carrying wire then the magnitude is not uniform however it is unidirectional for a region of space. Even if I use the maxwell's equations I'm just able to show that the magnetic field will be constant wrt to the direction in which its pointed...
 

 Mathematics

Associated with Math.SE; for both general discussion & math qu...
Jun 1 13:24
@BenSteffan yeah this, thanks a lot
Jun 1 13:23
hey guys how do i type a bidirectional arrow in latex? kind of like $\gets\to$ but them joined together
May 14 17:09
Hmm. Thanks for the help. I'll follow along your steps to see what I get. The answer I believe is 4R, which is why I believed there might be some short and neat method to get it done.
May 14 15:26
does anyone know how i can integrate this?
May 14 15:26
$$\int\limits_0^{2\pi} \int\limits_0^R \frac{r}{\sqrt{r^2+R^2 - 2rR\cos \theta}} \mathrm dr \mathrm d\theta$$
May 14 15:25
i need to integrate this
May 14 15:25
hey guys
Apr 15 18:12
hello
Apr 13 14:33
@Jakobian oh, totally missed it. thanks for the help.
Apr 13 14:09
Hey. I have a question. We have that $1<a_1<a_2 < \dots < a_{18} < 77$. We define $A = \{1,a_1, a_2, \dots, a_{18}, 77\}$ and that $B = \{x + y | x,y \in A\}$ and we're given that $B$ has exactly $39$ elements. Is it necessary that the $a_i$'s are in arithmetic progression? I have identified that $B=\{2, 78, 154, 1+a_1, 1+a_2, \dots, 1+a_{18}, 77 + a_1, 77+a_2 , \dots 77+a_{18}\}$ since all these elements are distinct and formed by taking sums of some two elements in $A$.
Mar 2 13:47
@nickbros123 i believe it is actually quite elementary, I hope I'm not overlooking something.. $x^k \equiv 1 \pmod p$. Then the multiplicative order $\operatorname{ord}_p(x) \mid k$ and also $\operatorname{ord}_p(x) \mid p-1$. Then $\operatorname{ord_p(x)} \mid \gcd(p-1,k)=1$, which means $\operatorname{ord}_p(x) = 1$ and so $x\equiv 1 \pmod p$.
Feb 28 22:06
@Thorgott thanks managed to do it
Feb 28 09:36
I managed to do it invoking dirichlet's theorem on primes on arithmetic progression, but I believe that must be an overkill
Feb 28 09:30
Hey. Does anyone know a proof that $x^k - 1 \equiv 0 \pmod p$, where $p$ is a prime and $k$ a positive integer coprime to $p-1$, has the only solution $x\equiv 1 \pmod p$?
 
May 20 12:30
@Integreek my teachers were also saying the exam was quite lengthy. i've not gone through the complete paper yet, just math, and I found quite a few time consuming questions, esp. in paper 2
May 18 11:30
hope your jee advanced went well seniors
Feb 14 14:35
@RajdeepSindhu right. i know graph theory is particularly useful in CS
Feb 14 13:54
@Anindo hi
Feb 13 16:17
@DarthVader oh well, are you taking the april attempt or straight to advanced?
Feb 11 18:11
@RakshithPL He did give some details about some months back. His JEE story is insane. His math hard-carried him throughout JEE. He's for math and math is for him
Feb 11 16:47
see you
Feb 11 16:47
@RajdeepSindhu 😂
Feb 11 16:42
I wonder how they decide so early on that they'd take science stream after 10th
Feb 11 16:42
there's students these days who've been with coaching institutes like Allen since 5th grade
Feb 11 16:37
what about you?
Feb 11 16:37
@RajdeepSindhu just preparing for finals and starting 12th
Feb 11 16:33
@RakshithPL congratulations
Feb 11 16:09
@RakshithPL how were the results?
Feb 7 20:18
@DarthVader hi, long time no see; how was your JEE main? Took me a while to figure out your username..
Feb 7 20:16
@MathGuy Hello
Jan 20 16:33
I found the question paper rather tough, more so than 2024's, and something like 2023's difficulty, but that might be just me...
Jan 20 16:32
Also, do you have some ideas about the cutoff?
Jan 20 16:32
What about you?
Jan 20 16:32
@DS I could really only do the first question, and some other partials, so I'm expecting somewhere around 20..
 

 In the search of a question

When you are looking for a specific question (using Approach0 ...
May 5 08:55
approach0 is still down? :(
 

 This Is Fine

The news discussion offshoot of the Bridge. Stars reserved for...
Mar 2 12:35
Mar 1 20:53
After JD Vance accused Zelenskyy of not being grateful for aid, he's personally thanking every leader showing support to Ukraine. x.com/ZelenskyyUa
Mar 1 07:51
Mar 1 07:24
European Union foreign policy chief Kaja Kallas :"The free world needs a new leader" x.com/kajakallas/status/1895570098834063878
Mar 1 06:33
@Memor-X I don't think so. waaytv.com/video/…
Feb 28 21:48
it's such a tragedy for the world's oldest democracy, with its highest elected executive proclaiming himself king on social media with supports justifying it as "trolling libs"
Feb 28 21:48
@User1865345 oh yeah, twice impeached too
Feb 28 21:45
@User1865345 he should've been investigated then, no? investigate him, and if he's indeed some Russian asset then at least don't let him run for the position thrice
Feb 28 21:40
I don't understand why Trump being American, would go to such limits to undermine every one of his allies and support Russia whenever possible. Its as if Russia has something on Trump. This is really appalling.
 

 Agora

General discussion for politics.stackexchange.com
Feb 7 21:08
If something like this happened in our country, the entire bureaucratic system would go on strike and government functioning would probably come to a halt.
Feb 7 21:07
I'm not American, and being an outsider I was more receptive to Trump's overall campaign -- no biological men in female sports, no illegal immigration, etc. But this whole DOGE this is so insane and crazy.
Feb 7 21:06
is it legal for Elon Musk to be going to govt agencies with literal kids and be shutting it down like he is doing?
 
Jan 3 17:39
Happy New Year Martin!