National Science Olympiad Forum By SOF Olympiad Trainer - Page 640
  1. Home
  2. /  Forum

User Forum

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

Ans 1:

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

Ans 2:

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 3:

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 4:

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

Ans 5:

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

Ans 6:

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

Ans 7:

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

Ans 8:

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

Ans 9:

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

Ans 10:

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

Ans 11:

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.

Ans 12:

Ishaan singhal from CCWS, Jaipur
Class : Class 3
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 13:

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

Ans 14:

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

Ans 15:

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 16:

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

Ans 17:

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

Ans 18:

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 19:

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

Ans 20:

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 21:

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

Ans 22:

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

Ans 23:

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

Ans 24:

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

Ans 25: (Master Answer)

Admin from revisewise, Noida
Class : Class 1

Post Your Answer

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

Ans 1:

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

Ans 2:

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

Ans 3:

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 4:

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 5:

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

Ans 6:

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

Ans 7:

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

Ans 8:

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

Ans 9:

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

Ans 10:

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

Ans 11:

Prabhav Kaushik from DPS Noida, Noida
Class : Class 10

Ans 12:

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

Ans 13:

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 14:

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

Ans 15:

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

Ans 16:

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

Ans 17:

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

Ans 18:

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 19:

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

Ans 20:

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

Ans 21:

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

Ans 22:

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

Ans 23:

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

Ans 24:

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

Post Your Answer

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

Post Your Answer

from , Kolkata
Subject :NSO    Class : Class 7

Ans 1:

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

Post Your Answer

from , Kolkata
Subject :NSO    Class : Class 7

Ans 1:

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

Post Your Answer

Raghav Mittal from DAV Public School, ludhiana
Subject :NSO    Class : Class 5

Ans 1:

Mallika Gupta from NPS indiranagar, Bangalore
Class : Class 9
it needs to be sedimentation and decantation because the insoluble material present in the liquid is quite heavy you only perform filtration when the particles float over the surface of the water

Ans 2:

Shivangi from St. Michael's High School, Patna
Class : Class 5
Ya, filtration can also remove insoluble impurities but in this case sedimentation and decanation is more appropriate answer.

Ans 3:

ARNAV GARG from PRUDENCE SCHOOL, New Delhi
Class : Class 10
c

Ans 4:

A Andrew from Lalaji Memorial Omega International School, Chennai
Class : Class 5
sedimentation and decantation is the answer . but filtration can not come because we can see in the picture itself that the particles are big ,that's why sedimentation and decantation . if the particles are small but yet insoluble , then only it is filtration . I hope that you understood.

Ans 5:

Gauri Singh from St. John's School, Marhauli, Varanasi
Class : Class 10
Yes, but in the given figure it is sedimentation

Post Your Answer

from , Kolkata
Subject :NSO    Class : Class 7

Ans 1:

Medha Bhutani from Christ Academy, Bengaluru
Class : Class 9
every single sound has its own secondary waves, so the correct option must be option C.

Ans 2:

RAHUL S ROY from ST.XAVIERS HIGH SCHOOL,VAPI, VAPI,GUJARAT
Class : Class 7
correct option is c

Post Your Answer

Ethel shiju from National Public School Indiranagar, Bangalore
Subject :NSO    Class : Class 8

Ans 1:

arnav from the gurukul, Panchkula
Class : Class 5

Ans 2:

Yash Bindal from Global Indian International School, Singapore
Class : Class 9

Ans 3:

Soham from Vibgyor high, Pune
Class : Class 8

Ans 4:

Bhuvanesh Singla from SCTS, Bengaluru
Class : Class 8
Hi, the statement 2 is true but just tells about the type type combustion to which the reaction given in statement belong. it does not tell about actual cause of burning of phosphorus in air at room temperature. the reason for statement 1 is that phosphorus is a highly reactive element that's why burns in air at room temperature.

Ans 5:

Divij Narang from ,
Class : Class 9

Ans 6:

Vihaan Nair from Ambassador School, DUBAI
Class : Class 8
Actually, the solution is opposite to the correct answer

Ans 7:

Student from School, City
Class : Class 8

Post Your Answer

Ethel shiju from National Public School Indiranagar, Bangalore
Subject :NSO    Class : Class 8

Ans 1:

SIDDHI SHREYASH from Phoenix Green International School , Hyderabad
Class : Class 8

Ans 2:

Aadavamoorthy from Advaith International Academy, Hosur
Class : Class 9
Both Wheat and Maize require rotation of crops.

Ans 3:

S V Harini from Vailankanni public school , Krishnagiri
Class : Class 8
Think in the way of leguminous crops

Ans 4:

Paarth Vashistha from Kunskapsskolan Gurgaon , Gurgaon
Class : Class 8

Ans 5:

Sahasra Shanker from KV IIT, Chennai
Class : Class 6
yeah right Triguna!!! in both cases soybean is present? why so?

Ans 6:

Sumedha Mishra from xyz, School, Pune
Class : Class 8

Ans 7:

Anshuman D from MVM, Hyderabad
Class : Class 9
Supposed to be only ABecause mustard is a non leguminous plantEven it can be rotated with soyabean

Ans 8:

MandarPalkar from KV DRDO, Bangalore
Class : Class 8
The protein requirement of mustard is fulfilled by the ribozome present in root nodules of soyabean?

Ans 9:

Triguna from Kendriya Vidyalaya No.1 Salt Lake, Kolkata
Class : Class 8
Why so? In both the cases soybean is present.

Ans 10:

Aadavamoorthy from Advaith International Academy, Hosur
Class : Class 9

Post Your Answer

Anurag Basistha from Prudence School Dwarka 16 B, Delhi
Subject :NSO    Class : Class 6

Ans 1:

Hamsavarshini Swaminathan from St Anns Senior Secondary School, Roorkee
Class : Class 10
iT IS NOT LAPTOP'S MISTAKE IT IS THE WEBSITE'S MISTAKE ITSELF.

Ans 2:

Bhabani Prasad from Narayan School, Kolkata
Class : Class 6
They did not give options on my ipad .

Ans 3:

Kshitij from Sams, Bangalore
Class : Class 6
they MUST and SHOULD be more CAREFUL. No options??? Then, how should we answer their question??? they take no actions! look:-a person has commented a year ago but?NO RESPONSE

Ans 4:

Ishaan Mishra from Sai International School, Bhubaneswar
Class : Class 7
I typed in c. What is this?

Ans 5:

Ritika Bakshi from Techno India Group public School Hooghly, Chinsurah
Class : Class 7
Want option!

Ans 6:

Aarush Laddha from NCFE, bengaluru
Class : Class 6
They did not provide options on my laptop but option C is correct.

Ans 7:

Riddhi from St Ursula high school, PIMPRI CHINCHWAD
Class : Class 6
No options

Ans 8:

Naman from Svm, Nalasopara
Class : Class 6
options are missing

Ans 9:

Ankush Ghosh from DPS, Doha
Class : Class 10
no options

Ans 10:

Anmol kathar from deogiri global academy, aurangabad
Class : Class 10
they didn't given on question page so all my friends and I missed that question

Ans 11:

Hamsavarshini Swaminathan from St Anns Senior Secondary School, Roorkee
Class : Class 10
They did not give options so that is why it went wrong. these kind of incidents happen very frequently in SOF

Ans 12:

Bharat from Geetanjali Olympiad school, Bangalore
Class : Class 9
they did not give options

Ans 13:

Hamsavarshini Swaminathan from St Anns Senior Secondary School, Roorkee
Class : Class 10
NO OPYIONS!

Ans 14:

BHAVYA JHA from GLOBAL CITY INTERNATIONAL SCHOOL, BANGALORE
Class : Class 6
they should be more careful

Ans 15:

Souvik Bhattacharya from MVM, Hyderabad
Class : Class 10
I got the question with the options in my laptop. For those who did not get the options : it is the website's fault

Ans 16:

Shourya Ganesh from The Green Acres Academy, Mumbai
Class : Class 9
they didnt give the options

Ans 17:

Raghav from Shalom Hills International school, Gurgaon
Class : Class 6
They're not even giving me options

Ans 18:

Sharmi Chowdhury from G.D Birla Centre For Education , Kolkata
Class : Class 7
They didn't give options

Ans 19:

Arnav Raj Sharma from GEMS International School the ultra master mega, Gurgaon
Class : Class 7
my laptop din't provide the options

Ans 20:

Pulkit Krishna from St. Paul's High School, Hajipur
Class : Class 6
The shadow will be whole black as the book is an opaque object and will not allow any light to pass through it so on the screen it will form a shadow. And the rest that is the ring, no light will reach it thus how can its shadow be formed?

Ans 21:

Ahaan Pathak from Treamis World School, Bangalore
Class : Class 8
they didn't give the options to my computer

Ans 22:

Shourya Ganesh from The Green Acres Academy, Mumbai
Class : Class 9

Ans 23:

khushi Joshi from Svkm , Mumbai
Class : Class 10
They did not give the options on my iPad so I couldn't see which was the correct ans. something needs to be done about this problem.

Ans 24:

Aniket Ghosh from DAV Public School Haldia, Haldia
Class : Class 9

Post Your Answer