National Science Olympiad Forum By SOF Olympiad Trainer - Page 649
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Mrinal garg from St. Joseph's Convent senior secondary school, Bathinda
Subject :NSO    Class : Class 8

Ans 1:

Sainyam Sharma from Thakur Public School, Mumbai
Class : Class 8
positive charge is acqired

Ans 2:

Advika Narkar from The Shishukunj International School, Jhalaria Campus, Indore
Class : Class 8
The options given here are a plastic scale,a woollen cloth, an inflated balloon and a COPPER rod, not a GLASS rod. How can the options appear differently for others, since many people here are saying that there is glass rod involved? Also, plastic is an insulator of electricity, so ideally it wouldn't acquire any charge, right? SOF should give a solution to this problem.

Ans 3:

Akshara from NPS, Bengaluru
Class : Class 8
Answer is A... positive charge is acquire by the glass rod

Ans 4:

Ethel shiju from National Public School Indiranagar, Bangalore
Class : Class 9
When rubbed with fur, glass will become negatively charged. However if silk is used instead of fur, glass will acquire a positive charge.

Ans 5:

Srikar from SSRVM, Bangalore
Class : Class 9
glass rod when rubbed with fur, it gives electrons to fur and becomes positively charged

Ans 6:

Aham from vibgyor high, Bangalore
Class : Class 8
This is wrong, yet nothing has been done to fix it. It has been discovered to be wrong FOUR YEARS ago!

Ans 7:

Vihaan Nair from Ambassador School, DUBAI
Class : Class 8
Plastic is unable to be charged.. Wrong answer!

Ans 8:

The Address from Somaiya, Mumbai
Class : Class 6

Ans 9:

meghna from Asan Memorial Senior secondary school, Chennai
Class : Class 4

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Siddharth Mahesh from mdav public school , Hyderabad
Subject :NSO    Class : Class 8

Ans 1:

Aryaman Neb from Tagore International School, New Delhi
Class : Class 5
Why

Ans 2: (Master Answer)

Admin from revisewise, Noida
Class : Class 1
The correct answer is C.

Ans 3:

ANIKA SHUKLA from UDGAM SCHOOL FOR CHILDREN, AHMEDABAD
Class : Class 10

Ans 4:

ANIKA SHUKLA from UDGAM SCHOOL FOR CHILDREN, AHMEDABAD
Class : Class 10
Protons don't move.

Ans 5:

ANIKA SHUKLA from UDGAM SCHOOL FOR CHILDREN, AHMEDABAD
Class : Class 10

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Shivangi from St. Michael's High School, Patna
Subject :NSO    Class : Class 5

Ans 1:

sai ramakrishna GUDIMETLA  from AMM MATRICULATION HIGHER SECONDARY SCHOOL, Chennai
Class : Class 5
D

Ans 2:

Gauri Singh from St Johns School Marhauli, Varanasi
Class : Class 8
It should be option C. It should be discouraged.

Ans 3:

sai ramakrishna GUDIMETLA  from AMM MATRICULATION HIGHER SECONDARY SCHOOL, Chennai
Class : Class 5
D

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from , Kolkata
Subject :NSO    Class : Class 4

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Anvesh from navy Children school, mumbai
Subject :NSO    Class : Class 10

Ans 1: (Master Answer)

Admin from revisewise, Noida
Class : Class 1
The correct answer is D.

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Soham De from DPS, Nerul, Mumbai
Subject :NSO    Class : Class 5

Ans 1:

Hitanshi Behera from Loyola School , Bhubaneswar
Class : Class 4
iron-nickel alloy notable for its lack of expansion or contraction with temperature changes. hence all metals do NOT expand

Ans 2:

Bhargavi from Bethany, Bangalore
Class : Class 1
The answer is B because the question says that he HEATED both the metals (most metals expand on heating) and Y has expanded more than X

Ans 3:

Pratham Dave from GNS, Bangalore
Class : Class 7
B is the answer to this question

Ans 4:

Sanskriti Nagar from Rose Bud Academy, khagaria
Class : Class 5
B is the correct answer

Ans 5:

Anahita Baruah from DPS Bangalore East, Bengaluru
Class : Class 3
All metal expands on heating. Here metal Y expands more which leads to curling of both X and Y. B is the correct option.

Ans 6: (Master Answer)

Admin from revisewise, Noida
Class : Class 1

Ans 7:

Hitanshi Behera from Loyola School , Bhubaneswar
Class : Class 4
sof does not reply that is why we are confused

Ans 8:

Fareeha siddiqua from Janki Devi public school , Mumbai
Class : Class 5
b as Y expands more

Ans 9:

aditya parlewar from St. Xaviers High school , Nagpur
Class : Class 3
b

Ans 10:

Saipriya from Sankara, Chennai
Class : Class 9
B m kids because Y is only curled much . dont get angry

Ans 11:

shubhavi Dhondge from NPS, Banagalore
Class : Class 9
B is the answer

Ans 12:

Arav Gupta from Delhi Public School Gurgaon, Gurgaon
Class : Class 8
D or B not sure.

Ans 13:

Soumyaraj Roy from Kendriya Vidyalaya , Thiruvananthapuram
Class : Class 7
Sumit Singhal , this is a bimetallic metal . Here , the two metals cannot go away from each other . So here , if y expands than x will also expand , and if x expands than y will also expand . I am getting confusion between A and B .

Ans 14:

Satvik Agrawal from Delhi Public School, bhopal
Class : Class 5
D or B? please vote

Ans 15:

Arav Singh from Jyoti Niketan School, Azamgarh
Class : Class 6
b

Ans 16:

Srishti Rani from DBMS ENGLISH SCHOOL, Jamshedpur
Class : Class 5
cONFUSED IN d AND B

Ans 17:

aditya parlewar from St. Xaviers High school , Nagpur
Class : Class 3

Ans 18:

Shivangi from St. Michael's High School, Patna
Class : Class 5
C is the correct answer

Ans 19:

SHUBHANI LAKHERA from ANN MARY SCHOOL, Dehradun
Class : Class 5
B is the right answer

Ans 20:

Aarnav Grover from Anand Niketan Shilaj, Ahmedabad
Class : Class 9
d

Ans 21:

Ishaan Singhal from CCWS, Jaipur
Class : Class 5
as if we will contract metal x so it is not neccessery that y will contract if we contract metal y x has to be conyracted with it ans should be a

Ans 22:

ayush from kv no.1 dhanbad, Dhanbad
Class : Class 10
B

Ans 23:

Hitanshi Behera from Loyola School , Bhubaneswar
Class : Class 4
ans should be D as if metal x contracts and metal y expands then the 2 metals will bend inward an as an ellusion we see that y is longer than x

Ans 24:

Gauri Singh from St Johns School Marhauli, Varanasi
Class : Class 8
The answer should be opt.B

Ans 25:

Ashmi Narkar from The Shishukunj International School, Jhalaria Campus, Indore
Class : Class 9
B because if Y expands and X contracts, X will be a lot smaller than Y. Here, both are almost the same size.

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Kshitij Gupta from St Kabir din, Ahmedabad
Subject :NSO    Class : Class 8

Ans 1:

Chaitanya L K from SKCHEC, bangalore
Class : Class 8
Yes it is A

Ans 2:

Akshara from NPS, Bengaluru
Class : Class 8
Yes it should be A .

Ans 3:

Raghav Tyagi from birla vidya niketan, new delhi
Class : Class 10
my apologies for the previous explanation answer is : C

Ans 4:

Amol Athawale from WoodRidge High, aurangabad
Class : Class 7
i do feel that correct answer is A.as P has to be electroplated ,it must be on cathode(-ve).so,correct is =A

Ans 5:

Vartika Agarwal from Phoenix world school, Pune
Class : Class 9
I will go mad with the number of wrong answers in this website.. answer should be a. For example when a spoon has to be electroplated with copper, copper is ALWAYS ON ANODE and the spoon is ALWAYS ON CATHODE. Why different logic is used here?

Ans 6:

Raghav Tyagi from birla vidya niketan, new delhi
Class : Class 10
In reactivity series hydrogen is below zinc and is less reactive than zinc. As hydrogen below zinc therefore will reduce more and earlier than zinc , hence will go to cathode and zinc will reduced or deposit at anode. therefore P will be connected to R and Q to S.hence ans is :C

Ans 7:

Paarth Vashistha from Kunskapsskolan Gurgaon , Gurgaon
Class : Class 8
A

Ans 8:

Raghav Tyagi from birla vidya niketan, new delhi
Class : Class 10
thus answer is a

Ans 9:

Abhay Agarwal from St Francis School, Ghaziabad
Class : Class 9

Ans 10:

Abhay Agarwal from St Francis School, Ghaziabad
Class : Class 9
answer A

Ans 11:

Chatresh ramasai gudi from Bgsnps , Bangalore
Class : Class 8
Answer is a

Ans 12:

from Bhandari Public School, KHANDWA
Class : Class 9
The correct answer is AAAAAAA

Ans 13:

Prabhav Kaushik from DPS Noida, Noida
Class : Class 10

Ans 14:

aditya arora from Heritage Experiential Learning School, gurugram
Class : Class 8
it should be a

Ans 15:

Dhars from DPS EAST Bangalore , Bengaluru
Class : Class 10
the answer is wrong.....it should be a

Ans 16:

Anshuman D from MVM, Hyderabad
Class : Class 9
Yes the answer is A

Ans 17:

Amrit Biswas from INDUSVALLEY PUBLIC SCHOOL, Noida
Class : Class 10
What is the correct answer A or C ???????

Ans 18:

Bhagyesh Kamal from DPS, Mumbai
Class : Class 8
answer is a

Ans 19:

Nishtha Neelabh from Lok Puram Public School, Thane West
Class : Class 6
answer should be A, as hydrogen is not released at cathode if the other cation is Zinc or below in the electrochemical series

Ans 20:

tamojit das from techno India Group Public School , Chinsura
Class : Class 8
cation(Zn2 ) must be deposited to the cathode.

Ans 21:

Sounak halder from Kendriya Vidyalaya Cossipore, kolkata
Class : Class 8
the answer will be 'A'

Ans 22:

Bipasana from KV IIT Kanpur, Kanpur
Class : Class 9
It has to be A.

Ans 23:

Riya Singhani from BVB vidhyashram, jaipur
Class : Class 8
WWWWRRRROOOONNNNNNNNNNGGGGGGGGGGGGGGGGG

Ans 24:

Tanush from presidency east, Bangalore
Class : Class 5
And for this question must be A

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H KRITHIK from kendriya vidyalaya, chennai
Subject :NSO    Class : Class 3

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from , Kolkata
Subject :NSO    Class : Class 7

Ans 1:

Medha Bhutani from Christ Academy, Bengaluru
Class : Class 9
ans is c

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from , Kolkata
Subject :NSO    Class : Class 7

Ans 1:

Sriyansh from Surabhi , Hosapete
Class : Class 9
Plug key is also a type of switch.

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