The "Kishore Vaigyanik Protsahan Yojana" is an ongoing program started by the Department of Science and Technology, Government of India, to encourage students of Basic Sciences, Engineering and Medicine to take up research careers in these areas. The aim of the program is to identify and encourage talented students with aptitude for research.
ANS OF Q 34 IS STABLE EQUILIBRIUM FOR SURE.. SUBSTITUTE +VE AND -VE VALUES FOR X, ULL GET THE ANSWER.. THERE IS A MISTAKE IN Q.44 AND 59 THERE IS ALSO A MISTAKE IN Q.98 OF PHYSICS
I too think that Question number 34 in SX stream's answer is wrong. I should be neutral equilibrium. F=-dU/dx at x=0 F=0 i.e Hence U is either minimum or maximum Where F is force and U is the potential energy. We have d^2U/dx^2=-dF/dx or d^2U/dx^2=3ax^2+4bx^3 And at x=0 the second derivative of Potential energy is zero which means the function of the potential energy has a point of influxtion at x=0 which proves that the particle is at a neutral equilibrium. For stable equilibrium the potential function should assume a minima and for unstable equilibrium the same should assume a maxima and for neutral the point should be a point of influxtion. And therefore I think the answer should be neutral equilibrium
@Srikanth Er . Can you please clarify how you got the answer as stable equilibrium?.
dude.. why do you complicate this? its pretty simple... consider any SHM... we know all simple harmonic oscillators are at stable equilibrium... condition for SHM... a= -kx we know that a body in shm experiences zero force in mean postion... substitute x=o in given equation.. we get 0 we know that for any positive displacement ,there is an opposing force in shm.. substitute any +ve value of x, u get -ve force and vice versa for any -ve displacement.. hence the body is in stable equilibrium
About Q68 in SA. The answer is 'mgh' as the speed of the block is supposed to be constant. But is the answer 'µmgh/sin θ' WRONG? definitely? Afterall, energy dissipated in the work done.
If you can understand that "mgh" is the correct answer, how are you getting "µmgh/sin θ" too? I can't really figure out the reason behind your confusion.
In my view the answer key of following question are wrong ;
Q. 45 : Answer Key on your site 'B' ; Correct answer in my view: 'C'
Explanation : since PV =nRT , hence PV and T are proportional to each other and for constant n, the graph should be straight line passing to origin and not straight line parallel to X axis. Hence the graph shown in option 'C' is definitely wrong.
Q 56 : Answer Key on your site .C' ; Correct answer in my view: 'B'
Explanation: as it is a very dilute solution so in it H^+ ions provided by water are also counted.
concentartion of H^+=10^-8 + 10^-7 =10^-7(1+.01) =1.01* 10^-7
now pH= -log [H^+] = -log [1.01*10^-7] = -log10^-7 -log1.01 =7-0.04 =6.96 i.e. near to 7
Hence the answer C , i.e. PH = 1 CAN NOT BE CORRECT.
The cut off definitely won't be higher than 45, keeping in mind the increased number of student intake & more importantly the fact that there wasn't any negative marking last year. This makes a huge difference because then the students have to attempt only the questions which they are sure about.
Darwin is true but Dear Darwin students who are getting above 80 are only a few ones may be around 7-8 students and above 77 another 4-5 students, this means rank makers under 15-16 would be around 77+, so greetings you are among these till date ( Interview part is still remaining which too will count in it) Not all INO awardees are getting the same high marks, I would like to request all that while making note it would be better to write about the right stream as this is causing confusion while reading about various things namely cutoff, wrong questions etc. It is still unclear about the number of students who will be called for interview, hence correct cutoff is not that easy to guess even if we come to know most of the students marks as per the keys expected to be revised soon. any ways best wishes for results of written test and cheers
ACCEPTED CORRECTIONS ARE ON THE WEBSITE OF KVPY NOW. as below:
Stream SA Note: 1.For Question No. 45, the right answer is B or C .
2.For Question No. 56, the right answer is B .
Stream SB/SX Note: 1.For Question Nos. 44, 45, 59 and 82, students will be awarded full marks. 2.For Question No. 98, the right answer is B, C or D.
>>> Wonder why they have not accepted the SA Q.75 (i.e. Potassium Permanganate and KBr in aq. acidic medium reaction) option mistake. (5 moles of Br2 option is not present.)
It is said that marks will be awarded to all. In that case if a student attemt PHY, BIO, MATHS in first section while CHEM, BIO in second then his paper turns out to be 100+7=107(as 7 marks are to all 3 in chem(1st sec.) and 2+2=4 in maths n phy(2nd sec)).żT
45,56 and 75 are wrong.
ReplyDeletei have got following doubts in SX
ReplyDeleteQ34
Q44
Q59
Q119
no doubts regarding official answer key of SB/SX...
ReplyDeletegetting 62 according to the answer key...
but tensed about the cut off...
ans of q34 should be nuetral equilibrium
Deleteq44 is a printing mistake
q59 the c no. in the product is lesser than in the reactant
ANS OF Q 34 IS STABLE EQUILIBRIUM FOR SURE.. SUBSTITUTE +VE AND -VE VALUES FOR X, ULL GET THE ANSWER..
DeleteTHERE IS A MISTAKE IN Q.44 AND 59
THERE IS ALSO A MISTAKE IN Q.98 OF PHYSICS
q44 is not printed wrong...The vertical line in the + in option d is not visible
Deleteyup....mistakes..mistakes and mistakes...
Deletecheck out 103. the correct ans should be B, not C !!
I too think that Question number 34 in SX stream's answer is wrong. I should be neutral equilibrium.
DeleteF=-dU/dx
at x=0 F=0 i.e
Hence U is either minimum or maximum
Where F is force and U is the potential energy.
We have d^2U/dx^2=-dF/dx
or d^2U/dx^2=3ax^2+4bx^3
And at x=0 the second derivative of Potential energy is zero which means the function of the potential energy has a point of influxtion at x=0 which proves that the particle is at a neutral equilibrium.
For stable equilibrium the potential function should assume a minima and for unstable equilibrium the same should assume a maxima and for neutral the point should be a point of influxtion.
And therefore I think the answer should be neutral equilibrium
@Srikanth Er . Can you please clarify how you got the answer as stable equilibrium?.
@mrinimoy pal How is 103 wrong. The reaction happening should be SN2 and therefore inversion should happen . And that leads to the right answer
Deletedude.. why do you complicate this? its pretty simple...
Deleteconsider any SHM... we know all simple harmonic oscillators are at stable equilibrium...
condition for SHM... a= -kx
we know that a body in shm experiences zero force in mean postion... substitute x=o in given equation.. we get 0
we know that for any positive displacement ,there is an opposing force in shm.. substitute any +ve value of x, u get -ve force and vice versa for any -ve displacement.. hence the body is in stable equilibrium
@harikrishnan: go through NCERT chemistry text book(class XII, part II),page number 300. It is explained there....
DeleteAbout Q68 in SA. The answer is 'mgh' as the speed of the block is supposed to be constant. But is the answer 'µmgh/sin θ' WRONG? definitely?
ReplyDeleteAfterall, energy dissipated in the work done.
Yes. "µmgh/sin θ" is definitely an incorrect answer. The answer provided in the key is perfectly fine. However, 45, 56 and 75 are ridiculous.
DeleteYes u r absolutely right. I believe ur answer is correct.
Delete@Sountik: Why is "µmgh/sin θ" is definitely an incorrect answer? Pl. explain
DeleteIf you can understand that "mgh" is the correct answer, how are you getting "µmgh/sin θ" too? I can't really figure out the reason behind your confusion.
Deletein 75 and 46, if they are declared wrong by kvpy...will everyone get the marks or only those who have attempted these.
ReplyDeleteIn my view the answer key of following question are wrong ;
ReplyDeleteQ. 45 : Answer Key on your site 'B' ; Correct answer in my view: 'C'
Explanation : since PV =nRT , hence PV and T are proportional to each other and for constant n, the graph should be straight line passing to origin and not straight line parallel to X axis. Hence the graph shown in option 'C' is definitely wrong.
Q 56 : Answer Key on your site .C' ; Correct answer in my view: 'B'
Explanation: as it is a very dilute solution so in it H^+ ions provided by water are also counted.
concentartion of H^+=10^-8 + 10^-7
=10^-7(1+.01)
=1.01* 10^-7
now pH= -log [H^+]
= -log [1.01*10^-7]
= -log10^-7 -log1.01
=7-0.04
=6.96 i.e. near to 7
Hence the answer C , i.e. PH = 1 CAN NOT BE CORRECT.
Also none of the options of 75 are correct.
I presume cutoff for SA will be around 58 to 62. Please post your guess and expected marks.
ReplyDeletewhat would be the cutt off for SX.
ReplyDeleteI am gettin 60 without the corrections.
The cut off definitely won't be higher than 45, keeping in mind the increased number of student intake & more importantly the fact that there wasn't any negative marking last year. This makes a huge difference because then the students have to attempt only the questions which they are sure about.
ReplyDeleteHm. I'm getting 78, SA.
ReplyDeleteTop candidates for SA, likely :
Chaitanya Tappu, IJSO gold medallist and INMO topper 85+
Sagnik Saha INMO awardee 85+
There *are* a few people above 85. Most of them are INO awardees.
Darwin is true but Dear Darwin students who are getting above 80 are only a few ones may be around 7-8 students and above 77 another 4-5 students, this means rank makers under 15-16 would be around 77+, so greetings you are among these till date ( Interview part is still remaining which too will count in it)
ReplyDeleteNot all INO awardees are getting the same high marks,
I would like to request all that while making note it would be better to write about the right stream as this is causing confusion while reading about various things namely cutoff, wrong questions etc.
It is still unclear about the number of students who will be called for interview, hence correct cutoff is not that easy to guess even if we come to know most of the students marks as per the keys expected to be revised soon.
any ways best wishes for results of written test
and cheers
are they doing ny changes in the answer sheet....??
ReplyDeleteTheres another mistake in the SB/SX paper that almost thats hard to notice.
ReplyDeleteQ.109
Theres another problem in sb/sx
ReplyDeleteQ.109
ACCEPTED CORRECTIONS ARE ON THE WEBSITE OF KVPY NOW.
ReplyDeleteas below:
Stream SA
Note:
1.For Question No. 45, the right answer is B or C .
2.For Question No. 56, the right answer is B .
Stream SB/SX
Note:
1.For Question Nos. 44, 45, 59 and 82, students will be awarded full marks.
2.For Question No. 98, the right answer is B, C or D.
>>>
Wonder why they have not accepted the SA Q.75 (i.e. Potassium Permanganate and KBr in aq. acidic medium reaction) option mistake. (5 moles of Br2 option is not present.)
2MnO4- (aq) + 16H+ (aq) +10e -> 8H2O (l) + 2Mn2+ (aq)
10Br- (aq) -> 5Br2 (aq) + 10e
2MnO4- (aq) + 16H+ (aq) + 10Br- (aq) -> 8H2O (l) + 2Mn2+
(aq) + 5Br2 (aq)
This comment has been removed by the author.
DeleteIt is said that marks will be awarded to all. In that case if a student attemt PHY, BIO, MATHS in first section while CHEM, BIO in second then his paper turns out to be 100+7=107(as 7 marks are to all 3 in chem(1st sec.) and 2+2=4 in maths n phy(2nd sec)).żT
ReplyDelete@bitbyte: When will result of KVPY be declared? What will be expected cut off of sb/sx? I m gettin 48. Any chances??
ReplyDeletewhen's result coming.?
ReplyDeleteSERIOUSLY HOW LONG DOES IT TAKE THEM TO PUBLISH ONE RESULT?
ReplyDeletelst year rslt was declared on 2 dec. dont know what they are trying to do this time.
ReplyDeleteresults expected by mid of next week; may be on 4th or 5th ; best wishes to all
ReplyDeletewhen is it coming?
ReplyDeleteresults will only come by 15th of december acc. to the kvpy official.... these people take longer than the IIT to display results
ReplyDeleteno they said it would come at the end of this week.
Delete@Srikanth Er...what is the source of your information??
Deletetoday i had been to kvpy office it was told that results will be available by 15 th dec
ReplyDeleteruthwik