First of all congrats to all those who have been selected for the interview.Its indeed a great achievement as lot many appear in this prestigious exam .So we have abt 1-2 months left for the interview.So you guys can give suggestions on the interview like which subject to choose,questions related to that etc.I welcome suggestions from you all.From my school we have got 46 selections in which 32 are from SA and rest from sx.

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TopNewestSo the kvpy interview is over.I am gonna share my experience.For me it was scheduled to be held at 9:00 am in NISER,Bhubaneswar. I reached there by 8:15.quite a far place.abt 22km from Bhubaneswar.It was adjacent to IIT,Bbsr.My interview started at 9:45 am after the completion of 2 students.The first one is a friend of mine(I don't know him much) who said after his that the interview board is quite friendly.that seemed a good gesture.So when I entered I just introduced my self,what I liked to do.etc.They asked what I had for breakfast and it was maggi for me.so they readily asked(chem) what chemical led to the controversy in maggi case.I didn't know.but anyways the person had himself told that this is not related to interview.so now of started.my topic was wave-particle duality,photoelectric effect and modern phy....somi was asked to explain photoelectric effect.on board which I did.then the physics prof asked me to split the work function into constituents.I did that it was binding energy+energy to remove that from the influence of all other interacting forces.then the mam asked on wave prop.then maths.I knew him as he is the director of institute of maths(where I had attended inmotcs in class 10,11)even he had felicitated me this yr for being 3rd in state in rmo.so he asked to prove that sum(j^99)j=1,2,3,4,5.was divisible by 5.I did that quite easily and could even generalise the case although it wasn't asked.the interview board seemed quite happy.I proceeded to factorise and proof the generalisation. And he didn't allow me to complete as he saw the first few steps and said "oh come on you can do after this quite easy" then something on relations.which I replied that I have not studied.and he said that it wasn't a big thing.I could do it anytime.then I was asked some conversions in organic although I didn't know them he didn't tell much and asked what I will do in future I said that I will do research (in mathematical aspect of physics) and they seemed quite impressed.and the next was a staple q(do you really want to join jee or do research)I genuinely replied research(as that's what I really wanna do).it came to an end and theybjust asked if I wanted anything to get clarified. I just asked what I can do to promote my interest as a student.The chem one replied that I was doing really well and I will do so.that made me feel quite ecstatic.and that was the end.later the director of niser(perhaps)wanted to meet my father.as he seemed to be quite happy with my perforomance.Later I went to canteen(some drinks)and returned.Believe me it was very big and great campus.and on way I even went to IIT bbsr.it is still under construction.nothing much but the field there is quite big.and it will look beautiful after some years. – Spandan Senapati · 3 months, 1 week ago

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– Swapnil Das · 2 months, 3 weeks ago

Any idea about what he told your father?Log in to reply

– Spandan Senapati · 2 months, 3 weeks ago

No nothing much he asked me where is your father.I just introduced him.And he told something which I didn't hear awe stood a bit away from him...He seemed to be a good person.Log in to reply

– A E · 2 months, 3 weeks ago

Can you please help me? A particle of mass 'm' moves under a force given by F= -kx^n.Find time period of oscillations if spring constant is k. Here n is any odd integer.Log in to reply

– Spandan Senapati · 2 months, 3 weeks ago

Ya its of the form \(8x(o)^((1-n)/2)/w(n+1)int(sin@^\((2/n+1)d@)\)).with @ varying from \(0-π/2\) and \(w^2=2k/m(n+1)\) Here the numbers \(2/n+1)\)accompanying \(sin@\) is the power that sin has been rairaised to.and the no\(1-n/2\)accompanying the x(o)term is a power .Log in to reply

– Harsh Shrivastava · 2 months, 3 weeks ago

Why will it not depend on amplitude?Log in to reply

– Spandan Senapati · 2 months, 3 weeks ago

OK so it has a value of \((√π)/2T\((n+3)/2(n+1)\)/\(T(n+2)/(n+1)\)). T is the gamma functionLog in to reply

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– Spandan Senapati · 2 months, 3 weeks ago

Lot of messy stuffs involved..Just solving differentials.Not much n physics involved here I guess.Log in to reply

– A E · 2 months, 3 weeks ago

Can you please explain how to derive time period from the beginning?Log in to reply

– Spandan Senapati · 2 months, 3 weeks ago

Ya it will intact the amplitude is the x(o)term.Hey try putting \(.sin@=e^(iy)-e^(-iy)/2i.\)Most probably the binomially expanding yieldmsome thing but then that's not in closed form. No don't work it becomes tedious.Log in to reply

– A E · 2 months, 3 weeks ago

What's m here?Log in to reply

– Harsh Shrivastava · 2 months, 3 weeks ago

Yup closed form does exist use beta function and then gamma function done.Log in to reply

r – Spandan Senapati · 2 months, 3 weeks ago

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– Harsh Shrivastava · 2 months, 3 weeks ago

I have not solved it till end.You may directly use beta function's defination to evaluate that integral.Just look up on brilliant wikis.Log in to reply

@A E Can you share pdf? – Prakhar Bindal · 2 months, 3 weeks ago

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– A E · 2 months, 3 weeks ago

I don't have it now,but it was in some PDF related to MIT's open course ware.Try googling it,I suppose its still on their site.Log in to reply

Thus it is worth learning even from jee point of view i guess. – Harsh Shrivastava · 2 months, 3 weeks ago

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– Prakhar Bindal · 2 months, 3 weeks ago

I learnt it coz i loved integrals when it was taught to us! and yeah that helped only in AITS :pLog in to reply

– Harsh Shrivastava · 2 months, 3 weeks ago

Did you had any backlogs at the end of class 11?Log in to reply

– Prakhar Bindal · 2 months, 3 weeks ago

Yep many i had . one of my backlog is still there which i haven't overcame FLUID MECHANICS . In chemistry i mostly didn't got Organic of 11th which i improved in 12th . in maths combinatorics troubled me and it still sometimes coz its a kind of topic which you cant master completely .Log in to reply

– A E · 2 months, 3 weeks ago

How did you solve it?Log in to reply

– Harsh Shrivastava · 2 months, 3 weeks ago

How did you do it?I tried doing it with normal integration and things are getting very tedious?Log in to reply

– Spandan Senapati · 2 months, 3 weeks ago

Ya substituted=x(o)(sin@)^(2/n+1).Although I don't know whether its closed form exists of the integral.But next let me ThinkLog in to reply

– Prakhar Bindal · 2 months, 3 weeks ago

Well this kind of problem has been asked in jee but was somewhat easier . If i can reckon correctly it had something proportionality constant (alpha)Log in to reply

– A E · 2 months, 3 weeks ago

I found this question in some PDF related to SHM.Log in to reply

– Harsh Shrivastava · 2 months, 3 weeks ago

Yup the problem mentioned smthing additional like small amplitude,i also remeber.Log in to reply

– Prakhar Bindal · 2 months, 3 weeks ago

Well i did SHM arhive in september 2015 but i marked that question coz i was not able to do that at first shot thats why i remember otherwise there are 100's of problems in archiveLog in to reply

Hence time period = 2pi*sqrt(m/kx^2) i know its not logical at all but one of professors of the panel told my friend this :P :P – Prakhar Bindal · 2 months, 3 weeks ago

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– A E · 2 months, 3 weeks ago

Did they tell the actual answer ?Log in to reply

Congrats! – Harsh Shrivastava · 3 months, 1 week ago

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– Spandan Senapati · 3 months, 1 week ago

No chance of top 10.I know a guy paean who is scoring as high in 90.and mine is 73.so its quite tough.but I expect a rank of within 100.BTW what's the highest in kvpy from yours state.I don't know sarthaks but his is mostly in 78-80.Log in to reply

– Prakhar Bindal · 3 months, 1 week ago

Yeah top 10 is really difficult . one of my friend got 86 in test and 64 in interview lasty year to get air 14Log in to reply

According to that if you equalise last year your rank will be in the range 25-50 (considering difficulty the same as last year).

I Got about 70 in test and 81 in interview ended with 59 .

My friend got 73 in test and 75 in interview ended with around 50. – Prakhar Bindal · 3 months, 1 week ago

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– Harsh Shrivastava · 3 months, 1 week ago

68-70 Nimay GuptaLog in to reply

– Spandan Senapati · 3 months, 1 week ago

Ohk.Log in to reply

Wish you all a prosperous holi! :) – Prakhar Bindal · 2 months, 2 weeks ago

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– Harsh Shrivastava · 2 months, 2 weeks ago

Happy holi to all 😀Log in to reply

– Sanyam Goel · 2 months, 2 weeks ago

Same 2 u bro .....Log in to reply

– Spandan Senapati · 2 months, 2 weeks ago

Yup same to you..........Log in to reply

Best of luck @Harsh Shrivastava.for your interview tomorrow.do share your experience tomorrow.just stay calm and give your best.you gonna rock it☺☺ – Spandan Senapati · 4 months ago

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– Harsh Shrivastava · 4 months ago

Thnx!Log in to reply

@Spandan Senapati @Harsh Shrivastava A question!

A parallel plate capacitor is completely filled with a dielectric sheet of thickness d and relative permittivity k is placed on a horizontal tabletop. The lower plate is glued with the tabletop and the dielectric slab is glued with the lower plate. The plates are square of edge length l and mass of the upper plate is m. The plates are given a charge +q and -q, then the upper plate is shifted horizontally by a small distance x along one of its edges and set free. Find the period of oscillation of this plate. Thickness d of the dielectric is much smaller than the edge length l. – Aniswar S K · 4 days, 14 hours ago

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– Spandan Senapati · 4 days, 2 hours ago

It would be better with a diagram. But I don't see what thickness means here. Anyways we begin by noticing that when the plates of a capacitor are displaced then the capacitance of the system is given by \(A\epsilon/d.\)where \(A\) is the projected common area.So Here \(A=L(L-x)\) . Now \(C=kL(L-x) /d\). Force by the other charges on this plate is \( F=-dU/dx\). \(U=Q^2/2C\).Note that the charge remains the same but \(\sigma\) changes..Using this you get \(ma=-kQ^2d/2m\epsilon L^3.\) Now that we have acceleration as negative means it's gonna come back to its natural position, overshoot and head to an amplitude, return back. So \(t=4\sqrt (2x/a)\) The constant \(4\) for in one complete cycle it covers\( 4x\) distance.So this yields\[ t=8L/Q\sqrt (mk\epsilon Lx/d) \] .I used d as the distance between the plates. God knows how it's the thickness. Lol. Got It? And the thing wrong in the previous solution was the expression for capacitance...Log in to reply

This means we must not expect everything to be shm!! – Aniswar S K · 3 days, 19 hours ago

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– Spandan Senapati · 4 days, 8 hours ago

I am sorry. It's incorrect. Didn't notice that the dielectric has thickness much smaller than the edge length....Log in to reply

– Spandan Senapati · 4 days, 9 hours ago

Try this way let an external agent displace the upper plate by a distance X then \[W(agent) +W(capacitor) =0\] .Since for an isolated system in the absence of dissipation forces the energy remains conserved. Now since electric force is conservative \(W(capacitor) =-dU\) Where the second term represents the change in potential energy. Since no external potential is applied\( U=Q^2/2C\).Now when we displace the plates by \(x\) say then \( U=L^2\epsilon /\sqrt d^2+x^2\).Now put that in the equation \(F=dU/dx\). and terms of the order \(x^2\) can be neglected. This gives \(F=\psi x\). But we don't have any agent performing so the force applied by other charges on this is \(f=-F\). So the plate exhibits SHM.Find \(T=2\pi /\omega\)Log in to reply

– Spandan Senapati · 4 days, 9 hours ago

Us the answer.\(.T=2\pi L/Q(2m\epsilon kd) ^(0.5)\).I solved using energy conservation as there would be fringing fields here and directly calculation of the force may be difficult....Log in to reply

– Aniswar S K · 4 days, 6 hours ago

In the answer there is a factor of 8. I don't know how they got it. T=(8l/q)(e0kmlx/d)0.5 and pi is not there!!Log in to reply

– Spandan Senapati · 4 days, 4 hours ago

Yes I know it's not gonna be a shy. It's gonna be a periodic motion with probably constant acceleration(I think) I will retry it.i didn't notice that the width of the dielectric is quite less. That's the error.Log in to reply

– Spandan Senapati · 4 days, 13 hours ago

Thanks let me try.Log in to reply

@shubham dhull

bhai ye dekh

https://www.change.org/p/cbse-do-lenient-in-cbse-physics-exam-2017-for-class-xii

Itna mushkil to nhi tha paper? – Prakhar Bindal · 2 months, 1 week ago

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– Shubham Dhull · 2 months, 1 week ago

ghanta mushkil tha :P agar 5-6 number grace de di to mere to 100 paar jayenge number :P balki set-3 tha sabse mushkil maine saare set dekhe the haina bhai ? tere kitne aajenge btade bhai plz ?Log in to reply

@Prakhar Bindal – Shubham Dhull · 2 months, 1 week ago

now i'm feeling bad about bragging too much without even knowing my real marks , just hope i get what i want btw math mein fatti padi hai bhai helpLog in to reply

@Spandan Senapati, @Harsh Shrivastava, @A E try this https://brilliant.org/problems/down-she-goes/ – Aniswar S K · 2 months, 2 weeks ago

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– Harsh Shrivastava · 2 months, 2 weeks ago

I am getting a non integral answer, I used energy conservation and the fact that since string is inextensible,velocity along them would reduce to zero though I may be wrong.Log in to reply

– Harsh Shrivastava · 2 months, 2 weeks ago

I also wrote momentum impulse equations.Log in to reply

– Spandan Senapati · 2 months, 2 weeks ago

And I guess we are gonna receive the Kvpy results soon.Let's hope for the best.Lastyr it was declared on 22nd.MarchLog in to reply

I am doubtful about mine. – Harsh Shrivastava · 2 months, 2 weeks ago

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– Spandan Senapati · 2 months, 2 weeks ago

Arey don't worry .You will get through as well...You qualified NTSE stage 2 as well I guessLog in to reply

– Spandan Senapati · 2 months, 2 weeks ago

I haven't tried it but is the bead fixed.Or the situation is just like a catenary.(chain hanging between 2 walls)Log in to reply

How was aiits? @Spandan Senapati @A E @Aniswar S K

I committed

so manysilly mistakes! :( Dont know when will i stop it :(Srsly i dont know why i commit so many mistakes :(

My score=20+27+48(cmp) – Harsh Shrivastava · 2 months, 3 weeks ago

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– Spandan Senapati · 2 months, 3 weeks ago

Ya.I checked the key it's so incorrect....Maths in a matrix I got-4(Hyperbola)The physics is wrong as well.Esp the first 2 questions.....(Now as per the incorrect key I got (33+25+57).Don't know but in maths the coefficient of(term independent of x is given wrong)...And they also gave that meso compound one wrong.Seriously I hate fiitjee exams for their incorrect answer keys.....Log in to reply

– Harsh Shrivastava · 2 months, 3 weeks ago

Yeah m,any are wrong i dont know why but in every exam it occurs :\Log in to reply

– Spandan Senapati · 2 months, 3 weeks ago

Oh yes you are right.I thought the ball was dropped when the other was at mean position.Rather its given that its the extreme........silly me.:)Log in to reply

– Harsh Shrivastava · 2 months, 3 weeks ago

Lol many of these kinds of mistakes are committed by me also.We must stop making these mistakes!Log in to reply

– Spandan Senapati · 2 months, 3 weeks ago

And the SHM was wrong as well energy will change as they stick...And time period and amplitude will change as well.......Careless people.Allen in this regard is grt.I have given n their xms twice and never was there a single wrong and.Log in to reply

See archive page number-65 jee advanced 2016 multi choice question 1 for a similar question. – Harsh Shrivastava · 2 months, 3 weeks ago

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– Spandan Senapati · 2 months, 3 weeks ago

We have a screwed up schedule here.I told you.Here they conduct exams from 6-9pm and they don't put the answer keys even.How did you get the answer keys......I will be telling tomorrow.Log in to reply

Overall howasit? – Harsh Shrivastava · 2 months, 3 weeks ago

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– Spandan Senapati · 2 months, 3 weeks ago

Maths was good.Chem seemed easy this time.Let's hope for best.Chill bro.I have exam tomorrow(chem practical)and I have bunked almost class(or absent).So I don't know even how do a simple salt analysis....(☺☺)And although I had done some in preparing for OCSc last yr I don't remember any.......Log in to reply

– Harsh Shrivastava · 2 months, 3 weeks ago

Hey spandan, one doubt in the question posted by aniswar , I solved it by iaor method.But then I tried solving by force torque method that is by drawing individual fbds but could not solve it.My doubt is what forces will act on the particle from ground frame?Log in to reply

– Spandan Senapati · 2 months, 3 weeks ago

Weight of the particle,contact forces by the rim..........But we need to analyse what sorts of acceleration it has.Log in to reply

– Harsh Shrivastava · 2 months, 3 weeks ago

I was doing a calc mistake, got my mistake, and yeah result is same in both cases ☺Log in to reply

– Spandan Senapati · 2 months, 3 weeks ago

Good....Were any answers wrong in phy and maths....Were did you get the keys fromLog in to reply

– Harsh Shrivastava · 2 months, 3 weeks ago

My center gave us key and some are wrong.I am posting solution to aniswars problem, do verify it.Log in to reply

– Spandan Senapati · 2 months, 3 weeks ago

Ya it went nice.In Physics I think one and didn't match.That rolling one It must be \((8/35)v/ug\).Log in to reply

– Harsh Shrivastava · 2 months, 3 weeks ago

I think answer is matching, coming out to be 3/7 v/ug many of my fnds also got 3.Log in to reply

– Spandan Senapati · 2 months, 3 weeks ago

Well the friction will change its direction may be I did some calc mistake but its like this initially it acts backward so time taken for w to become zero=(v/2R)*(2/5MR^2)/fR.=v/5ug.and for v to become zero its v/ug.So w becomes zero first then v=4v/5at that instant.Next friction supports rotation and opposes translation so 4v/5-ft/M=5ft/2M(t=8/35)OK then we needed to add with the initial.so that t=3/7..Oh I missed that......Got it thanks.Log in to reply

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– Harsh Shrivastava · 2 months, 3 weeks ago

Arey i tagged aniswar sk, dont know why you are tagged.Log in to reply

@Harsh Shrivastava.can you share with me some questions that theyasked you in your interview. – Spandan Senapati · 3 months, 1 week ago

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First they asked me C1+C2+C3+C4+....Cn prove this in two ways.

Then they asked a multinomial type question .

Then an easy physics question was asked.

Then some easy electrophilic addition question was asked.

That's all.Best of luck! – Harsh Shrivastava · 3 months, 1 week ago

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@Aniket Sanghi @Prakhar Bindal

How is class 12th jee preparation is it more difficult than class 11th?

My class 11 is about to end. – Harsh Shrivastava · 3 months, 3 weeks ago

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– Aniket Sanghi · 3 months, 3 weeks ago

Nothing is difficult in this whole world ... stop thinking about that and let the studies keep going...Log in to reply

– Prakhar Bindal · 3 months, 2 weeks ago

I Would not say difficult (class 12) just its a bit bigger than class 11 in terms of syllabus . but class 12 mostly has 55-60% weightage in JEE So you can understand its importance.Log in to reply

mine is 14. – Aniswar S K · 3 months, 3 weeks ago

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– Spandan Senapati · 3 months, 3 weeks ago

Hey looks like you qualified nsec.from your discussion.this is indeed a grt achievement considering the fact that you are in 11.which state and about your kvpy(when is it)Log in to reply

– Spandan Senapati · 3 months, 3 weeks ago

Mine is 14/2 =7th rankLog in to reply

in my school only 3 people have been selected 1 sa and 2 in sx – Aniswar S K · 4 months ago

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Yup all the best @Harsh Shrivastava

I Will give just one advice. clearly say if you dont know an answer . dont blindly guess . stay calm, cool take your time to think upon the problem. you will rock it – Prakhar Bindal · 4 months ago

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– Harsh Shrivastava · 4 months ago

Thnx!Log in to reply

Be confident , there main target is to check your confidence , they will try to just confuse you in your concepts itself and they will question you continuously , you just need to answer them with full confidence and correctness . And never answer those q which you don't know as wrong answers are not encouraged there and be upto the point , don't add extra waste things to your answer . – Aniket Sanghi · 5 months, 1 week ago

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– Piyush Kumar Behera · 5 months, 1 week ago

will bio question would be asked to a pcm studentLog in to reply

– Aniket Sanghi · 5 months, 1 week ago

I can't really gurantee that , but according to me they won't do such things . They understand the problem of students .Log in to reply

– Spandan Senapati · 5 months, 1 week ago

Thanx for your suggestions.will they be asking questions from all the 4 subjects.Log in to reply

– Aniket Sanghi · 5 months, 1 week ago

Depends , for me , they ask my favourite subject (Physics ) and then they asked for maths also .Log in to reply

– Spandan Senapati · 5 months, 1 week ago

What was your stage 1 marks?.does it any way matter in stage 2??Log in to reply

– Aniket Sanghi · 5 months, 1 week ago

My score was low due to Bio, it was 66.5 , however in second stage they dont ask your scores , they are not interested in that.Log in to reply

– Spandan Senapati · 5 months, 1 week ago

my score in bio is just 11.total 72.75.did you chose any special topic of interest for it??and tell me how did you prepare?we have got mock interviews organised by our school.And they call scientists for that even.so even those who qualify the first stage by a small margin perform well in interview.any way I am also planning to go with phy.Log in to reply

– Aryan Goyat · 4 months ago

11 is big no in bio my score was 0.75😂Log in to reply

My score in Bio was just around 6 :P – Aniket Sanghi · 5 months, 1 week ago

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Got 96% in CBSE Boards class XII . I Dont know how and became second school topper :P – Prakhar Bindal · 10 hours ago

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– Spandan Senapati · 10 hours ago

Nice...Congrats a lot.I don't know how much our school topper has but anyway of our hper result isn't good then its a bad omen for us....We will have to study in hper period that's the worst thing.Just to make clear we have 6 periods a week and our teacher doesn't come abt 5 times.He is very busy.....so its usually a bunk period for us.Log in to reply

@Spandan Senapati @Harsh Shrivastava Another one!!

https://brilliant.org/problems/tear-apart-the-dielectric/ – Aniswar S K · 4 days, 14 hours ago

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Keep posting more! I'll also post some! – Harsh Shrivastava · 4 days, 13 hours ago

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– Aniswar S K · 4 days, 10 hours ago

Actually I dont know how to solve them!!I am missing some small pointLog in to reply

– Aniswar S K · 4 days, 9 hours ago

Could you tell how you solved it??Log in to reply

– Harsh Shrivastava · 4 days, 7 hours ago

Even I have also not solved them, I am studying capacitors now, and will try to solve them after studying them.Log in to reply

– Spandan Senapati · 4 days, 2 hours ago

Hey I tagged you somewhere asking for help in a chemistry question where I was stuck with Hoffmann bromide or halo form reaction following first. Kindly help.. PlzLog in to reply

– Aniswar S K · 3 days, 19 hours ago

Sorry the notification is not coming. Could you pls give a link or tag again??Log in to reply

– Spandan Senapati · 3 days, 17 hours ago

https://brilliant.org/profile/aniket-5dxa59/sets/organ-blasts/434144/problem/be-careful-with-organic/. This one.Log in to reply

– Aniswar S K · 3 days, 15 hours ago

I've answered it there!!Log in to reply

– Spandan Senapati · 3 days, 14 hours ago

Thanks for the help. Keep in posting more chemistry questions. I haven't posted one yet.Log in to reply

– Spandan Senapati · 3 days, 14 hours ago

Hey heating of Hydroxy acids does yield cyclic product but when the OH is at the\(\alpha\) position to the carboxylic group you get a six membered ring. Here it's at \(\beta\) position you get an elimination product. So I guess the answer is Prop-2-en-oic acid. Thanks. I thought both halo form and Hoffmann bromide won't follow although adding H+ in the next step is an indication that halo form follows to yield a carboxylic group. ThanksLog in to reply

https://brilliant.org/problems/fun-with-ketones/ – Aniswar S K · 3 days, 14 hours ago

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@Harsh Shrivastava @Spandan Senapati

Try This and help me with a solution!!

https://brilliant.org/problems/potential-of-a-conducting-cube/ – Aniswar S K · 1 week, 6 days ago

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@Harsh Shrivastava @Spandan Senapati @A E a question

Electrostatic Potential at a point close to a charged conducting ball is V. When a very small conducting object ( a probe)

is brought at this point, potential of the ball changes by |deltaV|. Find force of electrostatic interaction between the ball and

the probe. – Aniswar S K · 1 week, 6 days ago

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– Spandan Senapati · 1 week, 6 days ago

What are the other parameters mentioned.....Like radius,charge on the ball etc.Log in to reply

– Aniswar S K · 1 week, 6 days ago

No Other Parameters. The Ans is 8pi(Epsilon)V|deltaV|Log in to reply

"Charges induced on the probe due to the electric field of the ball constitute an equivalent electric dipole. The field of this dipole is responsible to change the potential of the ball by an amount equal to potential created by the dipole at the center of the ball. Now consider interaction of this dipole with the electric field of the ball."

I considered that since the probe is very small the charge distribution on the ball is unaffected and i applied

F= p(dE/dx) where E= kQ/r^2 – Aniswar S K · 1 week, 6 days ago

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– Spandan Senapati · 1 week, 6 days ago

Yes it will do.You get \(8π\epsilon V\delta V=F\).Just to state \(\delta V=kp/R^2\) and \(F=2Vp/R^2\).I was considering that probe was a point charge so I was getting a bit weird result.But its conducting. so fine.Log in to reply

https://brilliant.org/problems/potential-of-a-conducting-cube/ – Aniswar S K · 1 week, 6 days ago

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@Spandan Senapati @Harsh Shrivastava @A E Sorry to Disturb

For us Differential Calculus got over.

Have you got any source for challenging problems??

I searched brilliant and mostly found integration problems! – Aniswar S K · 2 weeks ago

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BTW I guess there is an acute shortage of diferrential calculus problems ! – Harsh Shrivastava · 1 week, 6 days ago

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– Spandan Senapati · 2 weeks ago

For us definite integration is over.So I solve integration ones from Ronak aggarwals feed.Differential calculus I too want some good source.I think harsh can help us better.some questions from ronaks feed are quite tough.do try them.Log in to reply

– Aniswar S K · 2 weeks ago

Sure. Lets see what harsh has got to say!Log in to reply

@Spandan Senapati @Harsh Shrivastava Do u guys have any link to purcell electricity and magnetism 3rd Edition Solutions to exercises?? – Aniswar S K · 2 weeks, 1 day ago

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– Spandan Senapati · 2 weeks ago

No dont I have .I don't know ifits available.But you can post them here .Log in to reply

– A E · 2 weeks, 1 day ago

Like David morin's book solution or answers to exercises are unavailable.But you can post the questions here if you have any doubt.Log in to reply

– Aniswar S K · 2 weeks ago

Thanks. I will post if i hav some doubts.Log in to reply

@Spandan Senapati @Harsh Shrivastava Do you have a convincing proof of the following fact?

A point charge is placed inside a random cavity inside a conductor. Then the sum of the fields due to the point charge and the induced charges is zero for all the points outside the cavity.

I read Purcell. It is written that ' if we somehow remove the outer surface charge ' and then they proceed to prove the result which is fine, but how do you remove the outer surface charge in the first place?

If i assume on the contrary that the point charge and inner surface produce field inside a conductor, then this is not even a valid arrangement. We have to prove the fact. We are somehow assuming its true and then giving the proof.

Could you explain please??

It is confusing.! – Aniswar S K · 2 weeks, 5 days ago

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– Spandan Senapati · 2 weeks, 5 days ago

You probably didn't get the statement right perhaps.It means that the outer part is shielded from the inner.Means that the field due to the induced charges(here it means charges induced in the under surface not on the outer ones)+point charge is zero outside the vicinity of the conductor.Like take a very simple ex a point charge is placed at the centre of a spherical conductor then -q would be induced on the inner one and +q(if neutral on the outer one).Then the field due to -q(on the inner surface) and +q(point charge ) is quite clear to be zero for outside points(r>R).A similar argument says that the inner part is shielded from the outer.It means that the field at (r<R) is independent of the charges induced on the outer surface.Got it?Log in to reply

@Spandan Senapati @Harsh Shrivastava @Aniswar S K. Can you all please help me in thîs question .https://brilliant.org/problems/gauss-law-2/.What is the dirac Delta function and what is its significance here ? – A E · 2 weeks, 4 days ago

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– Spandan Senapati · 2 weeks, 4 days ago

I could have seen the q but the link isn't active in my phone.You know Greens Theorem(Divergence theorem)??That's a important theorem in vector calculus.Given a function we can calculate the divergence through(say a given volume )and this must equal the change thought he surface bounding it.Mathematically the integral \(\int \del .v(x,y,z) dV=S\int v.dA\).Here the second part denote a surface integral.But when the function falls as \(1/r^2\) something becomes fishy in terms of the integrals not being equal.For that we need Dirac delta function.Read any standard book on vector calculus and you will get it.Log in to reply

– A E · 2 weeks, 3 days ago

Sorry for disturbing ,but can you please tell me how do I solve questions related to parallel plate with moving plates.?Log in to reply

– A E · 2 weeks, 4 days ago

Is it given in grîffiths ?Log in to reply

– Spandan Senapati · 2 weeks, 4 days ago

Yes,Even even a more mathematical discussion if younwant then read Thomas Apostle(Multi variable calculus-vol-2).You will have it.Log in to reply

– A E · 2 weeks, 4 days ago

Thanks !!Log in to reply

@Spandan Senapati Why the outer part is shielded from the inner part for all possible shapes of conductors and cavities? What argument we use to generalize from a sphere to any shape? – Aniswar S K · 2 weeks, 5 days ago

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– Spandan Senapati · 2 weeks, 5 days ago

Hey it makes use of Circulation theorem.But the proof of shielding for an empty cavity is quite beautifully explained in Feynman's lectures..Its quite simple and uses some apparent symmetry of positive and negative charges.Try to read it or if you don't have I will try to explain.OK?Log in to reply

– Aniswar S K · 2 weeks, 5 days ago

Thanks!!. I read about the proof for shielding in empty cavity from Feynman Lectures.!Log in to reply

– Spandan Senapati · 2 weeks, 5 days ago

OK nice.I will read griffiths .let's see what it says..So that it becomes more clear.Log in to reply

– Harsh Shrivastava · 2 weeks, 5 days ago

The charge distribution inside the cavitiy occurs in such a manner that center of charge of induced charge coincides with our point charge. This happens so that electric field inside conductor is zero. The cavity along with our charge thus does not affect outside world directly. Got it?Log in to reply

– Spandan Senapati · 2 weeks, 5 days ago

Hey harsh aren't we going along two different lines.The one which I studied makes use of circulation theorem and you say centre of charge.And if it coincides then the mathematical argument must hold(the one with the integral as I said earlier).And for a general cavity the distribution being arbitrary we can't go on to evaluate the integral right.So circulation seems to be a cleaner argument.Isn't it?Log in to reply

– Harsh Shrivastava · 2 weeks, 5 days ago

Oh yes proving center of charge coinciding with +q is hell tedious. So the work done in round trip method is quite good.Log in to reply

– Spandan Senapati · 2 weeks, 5 days ago

Yes...And that's why coq as a concept isn't quite mentioned even in best books.there has to be symmetry to a great extent coupled with mathematical exactness.Log in to reply

– Aniswar S K · 2 weeks, 5 days ago

Where can i read about Circulation Theorem?Log in to reply

– Spandan Senapati · 2 weeks, 5 days ago

Itry electromagnetics by Griffith's.Better have some basics of Vector calculus.Thats surely gonna help.Log in to reply

– Aniswar S K · 2 weeks, 5 days ago

Thanks!!Log in to reply

– Spandan Senapati · 2 weeks, 5 days ago

Hey you qualified for Incho right.Can you tell what preparation is needed for chemistry Olympiad.I am gonna try to qualify it this time.Log in to reply

For second level i was doing previous year incho papers, old icho papers and preparatory problems.

For some special topics in organic chemistry like sulphur, silicon and phosphorous; radical and carbenes, heterocycles, Clayden is good.

After seeing the inorganic questions i was stunned. Maybe they expect us to guess new reactions based on our knowledge.! – Aniswar S K · 2 weeks, 5 days ago

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– Spandan Senapati · 2 weeks, 4 days ago

Nice I too study clayden.Thats a great book.So you must have like known the key concepts beforehand...So inorganic was tough this year.I saw that deuterium q.The first few ones seemed essy .Involved a little of modern physics.But further oneones were comparatively difficult.Log in to reply

– Aniswar S K · 1 week ago

How much special theory of relativity should we know before reading Purcell magnetism??Log in to reply

– Aniswar S K · 2 weeks, 5 days ago

My Sir also gave this explanation but didnt explicitly prove it .!Log in to reply

– Harsh Shrivastava · 2 weeks, 5 days ago

I think that if the COQ was not coinciding then a PD may arise inside conductor which is bad thus they have to coincide. Is there any flaw in reasoning here ?Log in to reply

@Harsh Shrivastava@Aniswar S K@A E.Do you guys have a smart solution for this problem "Conversion of Algebra To Geometry is an art".My method was quite lengthy although I got the and. – Spandan Senapati · 3 weeks ago

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@Spandan Senapati @A E @Aniswar S K – Harsh Shrivastava · 2 weeks, 6 days ago

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– A E · 2 weeks, 6 days ago

We too have it this MondayLog in to reply

– Spandan Senapati · 2 weeks, 6 days ago

We have abt 1 every week.Actually our course is on a full swing.So they prefer teaching more and sometimes we have tests.Now we are in Biomolecules(last chap of organic),Maths definiteint over physical magnetism abt to be over.Log in to reply

Hey let's post any good question if we come across in our tests OK? – Harsh Shrivastava · 2 weeks, 6 days ago

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– Spandan Senapati · 2 weeks, 6 days ago

Ya sure that's a good idea...Log in to reply

Whenever it comes for finding minimum distance inside triangle go for Fermat point. It is the point from where sum of distances to the sides is minimum. And here construct triangle with sides (0,0);(0,5);(12,0) and then find Fermat point which is the point such that <APB = <......=120°. I had a PDF which provided an awesome proof of it. – Harsh Shrivastava · 2 weeks, 6 days ago

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– Spandan Senapati · 2 weeks, 6 days ago

Yes I too used the concept of Fermat point but rather than finding the point I used cosine rule and a little manipulation.Log in to reply

@Spandan Senapati https://brilliant.org/profile/david-xee9sl/sets/gauss-law/37253/problem/more-gauss-practice-hard-2/ how to solve this?? – Aniswar S K · 1 month ago

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@Spandan Senapati - I got 66.75 in Aptitude test and 73.83 in Interview. The interview should have gone better!! – Aniswar S K · 1 month, 2 weeks ago

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@Harsh Shrivastava.@Aniswar S K.What are your marks in Kvpy?...The marks are available now.I got 72.75 in aptitude and 87.71☺in interview.Net 76.49. – Spandan Senapati · 1 month, 2 weeks ago

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@Spandan Senapati do you know sarthak behra's marks? I got 69 in apt and 96.14 in interview – Prathyush Poduval · 1 month, 1 week ago

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– Harsh Shrivastava · 1 month, 1 week ago

Awesome interview bro!Log in to reply

– Prathyush Poduval · 1 month, 1 week ago

Thanks!Log in to reply

– Spandan Senapati · 1 month, 1 week ago

Yes he got 82.5 in aptitude and abt 77in interview.Another friend of mine got 77.5 in aptitude and 78 in interview.She is air-17.Although that still amazes me how she got such a nice rank.Log in to reply

– Prathyush Poduval · 1 month, 1 week ago

thanks for the ranks! I am planning on running some statistics on it. Why are you amazed by her rank?Log in to reply

– Spandan Senapati · 1 month, 1 week ago

cause she herself agreed that she cheated from me.See our roll now are just consecutive.I didn't notice that as I was busy solving.And like she expected 55-60 in aptitude.Log in to reply

– Prathyush Poduval · 1 month, 1 week ago

oh my..... thats quite badLog in to reply

– Prakhar Bindal · 1 month, 1 week ago

This is the first time i am hearing someone getting >90 in interview . Well doneLog in to reply

@Prakhar Bindal Thank You! It was due to my interview I could get a very nice rank. – Prathyush Poduval · 1 month, 1 week ago

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– Spandan Senapati · 1 month, 1 week ago

Congrats...I am amazed by your interview score.To add a bit more to stats air-2 had 90 in aptitude testLog in to reply

– Prathyush Poduval · 1 month, 1 week ago

me too. what are his interview marks (air 2)?Log in to reply

– Spandan Senapati · 1 month, 1 week ago

I Don't know exact figures.Just aptitude marks I knew.AYou expected a top 50 rank BTW?Log in to reply

– Prathyush Poduval · 1 month, 1 week ago

Not at all! I was expecting around 120-170 rank with my aptitude marks..... but the interview increased my marks by a huge amountLog in to reply

– Prakhar Bindal · 1 month, 1 week ago

Well congrats a pretty high score in interivew.Log in to reply

I got 52.5 in aptitude and 63.2 in interview thus overall 54.99 (😢) if only I had one mark more... – Harsh Shrivastava · 1 month, 2 weeks ago

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– Prakhar Bindal · 1 month, 1 week ago

Dont worry dude. One of my friends didn't qualified last year . this year he is in top 50Log in to reply

– Spandan Senapati · 1 month, 2 weeks ago

I really feel sorry for you....Just 0.01....Doesn't matter..go ahead.. you are gonna kill SX this yr.Log in to reply

Why is induction due to point charge not considered here in this problem?

@Spandan Senapati @Aniswar S K @A E

This Problem – Harsh Shrivastava · 1 month, 3 weeks ago

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Area(for planar surface of course)If it induces charge On a certain surface then on any other it must be qand summing all these gives q.But unlike a spherical symmetry where the induction of charge would be symmetric the system given here might have different densities at diff point(if consider induction)and may be calculating the force becomes tedious by integration.So again physics is all assumptions that you make.For a sphere although using Image Charges is the most apparent way. – Spandan Senapati · 1 month, 3 weeks agoLog in to reply

@Harsh Shrivastava. Did you also have reshuffling test today??.What's your score.Chem answer key is incorrect in Mains.So haven't checked.So my marks Maths-106/120,Phy-96/120.Adv-Phy65/80,Math-60/80.Yours?? – Spandan Senapati · 1 month, 3 weeks ago

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How was the paper? tougher than previous? – Harsh Shrivastava · 1 month, 3 weeks ago

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– Spandan Senapati · 1 month, 3 weeks ago

Fine.Mains Physics was good yes both Maths and Physics were tougher than previous ones.Chem answers were incorrect in Mains so I didn't check..Have the prev ones results been released.I visited the microsite but what's Blind School.Log in to reply

@Spandan Senapati and @Harsh Shrivastava - do try this question

https://brilliant.org/problems/permutations-in-organic-chemistry/?ref_id=1343394 – Aniswar S K · 1 month, 3 weeks ago

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Thank You very much @Harsh Shrivastava and @A E.

You will definitely qualify next year.!! Cheers. – Aniswar S K · 1 month, 3 weeks ago

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– A E · 1 month, 3 weeks ago

Hope to do so.Log in to reply

I could not qualify :(

Congrats @Spandan Senapati @Aniswar S K – Harsh Shrivastava · 1 month, 3 weeks ago

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– Spandan Senapati · 1 month, 3 weeks ago

No problem...Just chill...Better luck next time.SX is still there..No rejoicing for me as well.Have another reshuffling test on Sunday.Log in to reply

@Spandan Senapati most probably i will come. What about you?? – Aniswar S K · 1 month, 4 weeks ago

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@Sarthak Behera.Great job buddy.You once again have made a stance... – Spandan Senapati · 1 month, 4 weeks ago

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@Spandan Senapati, @Harsh Shrivastava My rank is 119. – Aniswar S K · 1 month, 4 weeks ago

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@Spandan Senapati Congrats for AIR 24 and Sarthak Behera AIR 4.. – Aniswar S K · 1 month, 4 weeks ago

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– Spandan Senapati · 1 month, 4 weeks ago

Congrats to you as well...air 119 is great as well.You will come for Vijyoshi??Log in to reply

@Spandan Senapati and @Aniswar S K – A E · 1 month, 3 weeks ago

CongratsLog in to reply

– Spandan Senapati · 1 month, 3 weeks ago

Thanks lot...Log in to reply

– Prakhar Bindal · 1 month, 4 weeks ago

Do go there . Its worth going there . you will enjoy a lot and there will be fun + learning . Moreover your courses will be over by that time and only AITS Will be left hence no lose of fiitjee will be there. It was an unbelievable experience which i will cherish whole of my lifeLog in to reply

– Spandan Senapati · 1 month, 4 weeks ago

Yes I will.Bhubaneswar is quite close to Kolkata.It takes abt 6 hrs in a train and 30-40 mins in flight.Log in to reply

Trains took a full day as due to fog in northern india trains were late by 12 hours :P – Prakhar Bindal · 1 month, 3 weeks ago

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@Spandan Senapati Could you please upload a solution to the seiche problem?? – Aniswar S K · 2 months ago

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Hey @Harsh Shrivastava.Did you also have batch reshuffling on 26th h.The one with a easiest phy in jee mains and a good jee advanced paper.Is it 1618 CRP ABC LOT RT-1??We had it.. – Spandan Senapati · 2 months ago

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– Harsh Shrivastava · 2 months ago

How much are you scoring, if you want answer keys, you may check Fiitjee Bhilai microsite, click on batch formation test result link and then proceed.Log in to reply

– Spandan Senapati · 2 months ago

Yes we too have got the answer keys.Mine score 300(Mains)115/88/97(PCM).And 125(adv)(46/31/48)(PCM).Total 425(main+adv).What about you??Log in to reply

– Harsh Shrivastava · 2 months ago

I feel like few answers are given wrong.Log in to reply

– Spandan Senapati · 2 months ago

Your chem adv is great....Although that was difficult..yes area are wrong.I found 3(main+adv).And the phy in mains was quite easy.Couldn't score full.:(And maths yes same.Log in to reply

– Harsh Shrivastava · 2 months ago

I also commuted various mistakes in mains and in advanced, I lost 2 questions in maths due to my carelessness have to becareful next time.lLog in to reply

132 in adv(38/46/48)

Our scores in maths are quite same I have seen in many tests :P – Harsh Shrivastava · 2 months ago

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– Spandan Senapati · 2 months ago

Did you ever get full marks in class 11 fiitjee exams..I got only twice in phy and NVR in maths and chem..Log in to reply

Last year 3 people got 360/360 in reshuffling test. i didn't gave them.

The person who topped our centre got around 340 still his air was 20.

Similarly in advanced last year highest score was 198/210 and a friend got 160/210 and ended up with 100+ rank – Prakhar Bindal · 2 months ago

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– Spandan Senapati · 2 months ago

As I said I got full score in physics mains(reshuffling class 11) and Advanced (70/70)in phase 1 and 115 abt 2 times.In Maths my highest is 111(phase 3).Chem not yet....Log in to reply

In Advanced i have never got full in chem for obvious reasons :p . Most probably my highest score in chemistry advanced was like 84/100 in phase 5 :P

In Maths my highest score was 80/80 in phase 3 .

in physics i guess my highest is 76/80 in phase 3 .

In class 12th relatively papers became harder (especially phase tests) for preparing well for jee . i wont say about AITS . if someone scores even 30-35% in a subject in AITS he is well aware of all the concepts :p – Prakhar Bindal · 2 months ago

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– Harsh Shrivastava · 2 months ago

Never :(Log in to reply

– Harsh Shrivastava · 2 months ago

Yeah we too had that paper.Log in to reply

– Spandan Senapati · 2 months ago

It wasn't a sort of reshuffling for the CMP(batch-1)We had been told to appear only.Ours reshuffling is for the general batches and CMP(batch-2).And another one is on 2nd April.Isn't it?Log in to reply

@Spandan Senapati @Harsh Shrivastava what are your Aiits-4 ranks?? Mine is 114. Have to improve little next time. – Aniswar S K · 2 months ago

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When are the kvpy results coming – Aniswar S K · 2 months ago

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– Spandan Senapati · 2 months ago

My friend told that his father had called kvpy office and they told its most probably to come out on 2nd April...Delay is a bit clear to me as in our interviews they had not collected the mark sheet.Some had to send them later(including me)...So abt a week or so to go....Log in to reply

@Prakhar Bindal @Spandan Senapati @A E @Aniswar S K

This may be useful to you.Past year aits papers.

http://jeewizard.blogspot.in/2015/01/fiitjee-aits-2015-all-sets-of-question.html – Harsh Shrivastava · 2 months, 1 week ago

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How is TMH for maths?

@Prakhar Bindal – Harsh Shrivastava · 2 months, 1 week ago

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Algebra- AWESOME Simply awesome you can't get a better book than this

Coordinate geometry- too easy . definitely not of advanced level (especially conics straight lines and circles are too good but conics sucks in this book)

Calculus - Not too good . Arihant is too better

Vector 3D- Personally not tried it – Prakhar Bindal · 2 months, 1 week ago

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– Harsh Shrivastava · 2 months, 1 week ago

I ordered this book bcoz my coordinate is not strong.So what do you use for coordinate geometry?Log in to reply

– Prakhar Bindal · 2 months, 1 week ago

I Would recommend SK Goyal's Coordinate geometryLog in to reply

@Spandan Senapati I don't think the bead is fixed it can move – Aniswar S K · 2 months, 2 weeks ago

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@shubham dhull how was physics? – Prakhar Bindal · 2 months, 2 weeks ago

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– Prakhar Bindal · 2 months, 2 weeks ago

It was good . I Cant say about marks at all . Semiconductors was a bit bad . expecting for the best . 2nd april is a big day JEE Mains!!Log in to reply

– Shubham Dhull · 2 months, 2 weeks ago

acha bhai bye , meri physics hi thik h math me fatti pdi h pre-bord me 60 no. the , uski tyari krni h atleast 90-95 ke aas-ps to phuch hi jaoonga padke jauhga too.. best of luck broLog in to reply

– Shubham Dhull · 2 months, 2 weeks ago

thik ti yaar aimed for 100, itni zabardast tyari ti , fir bi 95-98 aage to mei bhut khush hu , teri ?Log in to reply

– Shubham Dhull · 2 months, 2 weeks ago

mera pre-board mei isse acha hua tha fir bi 67.5/70 aaye te considering bord ki checking 95 to aa jane chiye bhai. bas 1 glat hoga last Q , mhuje usme doubt h bataeo bhai :)Log in to reply

@Spandan Senapati I am sorry for underestimating the question! – Aniswar S K · 2 months, 2 weeks ago

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– Spandan Senapati · 2 months, 2 weeks ago

No problem.Take your time and if you do by force method it will be good as well..That is indeed a tough fluid mech question.....Log in to reply

@Spandan Senapati For that Seiche question. i tried like this when you displace by z (net pulling force)/ mass = acceleration. a= 2 z bh g/ lbh = 2zg/l T = 2pi/w=2* 3.14* (70000/2*10) ^ 0.5 = 6.19 minutes What is the mistake?? – Aniswar S K · 2 months, 2 weeks ago

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– Spandan Senapati · 2 months, 2 weeks ago

You can refer the book by AP French(MIT Introductory Physics Course).Log in to reply

– Spandan Senapati · 2 months, 2 weeks ago

And in systems as such its better to make use of energy conservation..And this question needs some more thinking.Let me give some hints(1-Eq of continuity 2)Co amputation of potential and kinetic energy of system(integrals).Force method is useful in systems where you are able to predict the behaviour of forces,their magnitudes etc.And here it will be quite apparent that analysing forces isn't quite easy....Log in to reply

@Harsh Shrivastava Shouldnt R be equal to sqrt2 r?? – Aniswar S K · 2 months, 2 weeks ago

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– Spandan Senapati · 2 months, 2 weeks ago

That's a upper bound that you can restrict the ration to be.But we need the best bounds.And that won't be possible for this process must be accompanied by some net heat exchange(Or else just a sort of ideal process.Violation of 2nd law).Log in to reply

Why is the answer 2.674 – Aniswar S K · 2 months, 2 weeks ago

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– Harsh Shrivastava · 2 months, 2 weeks ago

I think it is correct.What are you getting?Log in to reply

@Spandan Senapati @Aniswar S K @A E

Problem

I have posted a problem, do try it and verify weather it is correct or not. – Harsh Shrivastava · 2 months, 2 weeks ago

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– Spandan Senapati · 2 months, 2 weeks ago

What did you mean by best bound?Log in to reply

– Spandan Senapati · 2 months, 2 weeks ago

Ya I solved it.Rather put me first into thinking why T and P have not been given.But the question needs some cold analogy.Good.BTW You said to post some Mech q.I have posted 2 Fluids q...Try them esp the one "Seiche".That is something that we witness everyday but don't put into maths.Log in to reply

– Harsh Shrivastava · 2 months, 2 weeks ago

Hey in that utube question,can u plz attach a diagram?Log in to reply

– Spandan Senapati · 2 months, 2 weeks ago

I am unable to do that despite your telling meLog in to reply

– Harsh Shrivastava · 2 months, 2 weeks ago

Thanks! Will try your ques.Log in to reply

@Spandan Senapati -- in that 65th question how to relate the rate of increase of temperature and speed of piston?? i tried something like PdV + VdP = nRdT. dV=Adx & dP=kdx/A since P=kx/A. and then divide both sides by dt. but then i am not getting that 3/8 in the answer. – Aniswar S K · 2 months, 2 weeks ago

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– Spandan Senapati · 2 months, 2 weeks ago

Hey there is a thing that the piston is nt massless so Weca t equate the forces perhaps.Log in to reply

– Spandan Senapati · 2 months, 2 weeks ago

For 64 make use of the fact that the max theoretical increment in temperature accounts for the increase in internal energy =Increment in potential energy so \(nCv(T-To)=Mgh\) and \(nRTo=(p+∆p)V\).It's a valid supposition that initially the Tempnof the air inside is \(To\)Log in to reply

For finding the height should we use (PV ^ γ) = constant ?? – Aniswar S K · 2 months, 2 weeks ago

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@Spandan Senapati - Yah i got it now. First i considered even atmospheric pressure thats why i got some extra variables. Thanks. – Aniswar S K · 2 months, 2 weeks ago

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Did u solve?? Advanced Problems in School Physics – Aniswar S K · 2 months, 2 weeks ago

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– Spandan Senapati · 2 months, 2 weeks ago

Ya I s just saw and solved q 65.That's quite easy.Use conservation of energy for the entire system.We can find out the height h(but that would involve solving some hell weird exp) So they indirectly gave that h.And the other thing is simple the exp of the gas is adiabatic.Most of the qseem to be from energy conservationLog in to reply

https://plus.google.com/+AniswarSK/posts/X2voKbB5pEx – Aniswar S K · 2 months, 2 weeks ago

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@Spandan Senapati @Harsh Shrivastava can you try these out?? – Aniswar S K · 2 months, 2 weeks ago

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https://plus.google.com/+AniswarSK/posts/BbvETFvttbe – Aniswar S K · 2 months, 2 weeks ago

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Are you on Google hangouts? – Harsh Shrivastava · 2 months, 2 weeks ago

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– Harsh Shrivastava · 2 months, 2 weeks ago

Link is not opening, what is it?Log in to reply

@Spandan Senapati are you in slack?? – Aniswar S K · 2 months, 2 weeks ago

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– Spandan Senapati · 2 months, 2 weeks ago

No I am not active in any forum.Log in to reply

@Spandan Senapati which Allen exams did u write?? Are they at a better level these aiits – Aniswar S K · 2 months, 3 weeks ago

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Guys try this * Q https://brilliant.org/problems/all-mixed-up/?ref_id=1331154 – Shubham Dhull · 2 months, 3 weeks ago

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Hey @Aniswar S K,@Harsh Shrivastava.I got to know that we can intact challenge the answer keys online by creating an account so.Let me check – Spandan Senapati · 2 months, 3 weeks ago

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– Prakhar Bindal · 2 months, 3 weeks ago

www.fiitjeelogin.com then go to test performanceLog in to reply

– Prakhar Bindal · 2 months, 3 weeks ago

yep you can i had done it many many times in class 11Log in to reply

Around 105 For waves and heat transfer is not over. – Aniswar S K · 2 months, 3 weeks ago

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@Spandan Senapati Is the bottom most point the instantaneous centre of rotation?? If so shouldn't we consider torque of pseudo force?? – Aniswar S K · 2 months, 3 weeks ago

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– Spandan Senapati · 2 months, 3 weeks ago

Exactly you got it right.There is an acceleration \(w^2R\)so we need to apply a pseudo torque as well.Log in to reply

I saw this problem in GMP https://brilliant.org/problems/roll-and-roll/ – Aniswar S K · 2 months, 3 weeks ago

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– Spandan Senapati · 2 months, 3 weeks ago

Even I knew the answer.Quite easy.either write energy or differentiate or take torques about instantaneous centre of rotation.Rather taking the torques about the ICOR is short.Another approach would be to draw the fbds.and then take torques about individuals centre of massLog in to reply

– Prakhar Bindal · 2 months, 3 weeks ago

Well i haven't solved GMP Yet but its from my CPP And hence i even remembered the answer to the problem! :PLog in to reply

@Spandan Senapati I am getting around 57 in kvpy stage 1. And I know Siddharth Sridhar. We were in same institute last year. How did you come to know him?? – Aniswar S K · 2 months, 3 weeks ago

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– Spandan Senapati · 2 months, 3 weeks ago

Allen champ.Even I had been nominated but I was not in top 10.But he has a good record in Allen champ.Log in to reply

@Prakhar Bindal.@shubham dhull.@Aniket Sanghi.@Harsh Shrivastava.@A E.@Aniswar S K.Hey guys I am getting a different and .what are you getting????https://brilliant.org/problems/charge-redistribution/.For a simplistic version try the IPHO 2010 Theoritical problem 1. – Spandan Senapati · 2 months, 3 weeks ago

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– Prakhar Bindal · 2 months, 3 weeks ago

It seem all of us are quite habitual to this habit of silly errors. i too lost many points in AITS Open test due to my negligence and of course my laziness. What happened was i did physics pretty good which i attempt first (score 48/62) then got into chem . clean bowled didn't knew many Multi corrects . due to this made a bubbling error (4 marks puff!) . Then switched to maths again did well (43/62) . then came to chem at last . i could have scored easily upto 32/62 but got only 15 due to my silly errors and my laziness (i didn't got a nice sleep last night and hence slept from 12 pm to 12:30 pm in paper 1) :P (paper was from 9:30 to 12:30) . but somehow i came over this sleepiness and managed to remain awake whole paper 2 :PLog in to reply

– Spandan Senapati · 2 months, 3 weeks ago

I don't feel sleepy......☺☺☺Log in to reply

– Prakhar Bindal · 2 months, 3 weeks ago

Good you know i am lazy sometimes but i cant help it . Neend aati hai to aati hai main kya karun :PLog in to reply

– Spandan Senapati · 2 months, 3 weeks ago

Sach main....Bhai Jee main mat sona.....pichle din sleep well.Log in to reply

– Prakhar Bindal · 2 months, 3 weeks ago

Yep i will take care before JEE . If not I My mother will of course :PLog in to reply

– Shubham Dhull · 2 months, 3 weeks ago

lol of course , bro slack pe kb aayega ?Log in to reply

– Prakhar Bindal · 2 months, 3 weeks ago

After 21st MayLog in to reply

– Shubham Dhull · 2 months, 3 weeks ago

well i hope we wouldn't need it after advanced , we may land in the same IIT :PLog in to reply

– Prakhar Bindal · 2 months, 3 weeks ago

We can just work . Almighty will give us what we deserve . Hope so!Log in to reply

– Shubham Dhull · 2 months, 3 weeks ago

indirectly saying you don't deserve it :PLog in to reply

– Prakhar Bindal · 2 months, 3 weeks ago

Well i am somewhat philosophical guy .if i have worked hard and i deserve it i will certainly land thereLog in to reply

– Shubham Dhull · 2 months, 3 weeks ago

i am somewhat philosophical guy too ...aur wo line mere liye thi naki tere liye (of-course u r in better condition than me now.) i meant to say that i need to work hard to reach ur level.Log in to reply

– Harsh Shrivastava · 2 months, 3 weeks ago

I feel sleepy in second paper many times :PLog in to reply

From that day i have decided before any major test i will sleep max by 11 pm – Prakhar Bindal · 2 months, 3 weeks ago

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– Shubham Dhull · 2 months, 3 weeks ago

bhai tune computers le rka h ya physical ?Log in to reply

– Prakhar Bindal · 2 months, 3 weeks ago

Physical educationLog in to reply

– Shubham Dhull · 2 months, 3 weeks ago

maine computers le rhka h, mri pdi h :PLog in to reply

– Shubham Dhull · 2 months, 3 weeks ago

tell quickly i need togo ..Log in to reply

– Spandan Senapati · 2 months, 3 weeks ago

Although I solved that IPHO one .This one I got \(U=-kq^2/2(R/d)(1/R-1/d^2-R^2)\)Log in to reply