National Science Olympiad Forum By SOF Olympiad Trainer - Page 640

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Subject :NSO    Class : Class 5

Ans 1:

Class : Class 5
b as Y expands more

Ans 2:

Class : Class 5
B is the correct answer

Ans 3:

Class : Class 4
iron-nickel alloy notable for its lack of expansion or contraction with temperature changes. hence all metals do NOT expand

Ans 4:

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 5:

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:

Class : Class 5
C is the correct answer

Ans 7:

Class : Class 8
The answer should be opt.B

Ans 8:

Class : Class 5
cONFUSED IN d AND B

Ans 9:

Class : Class 3
b

Ans 10:

Class : Class 3

Ans 11:

Class : Class 8
D or B not sure.

Ans 12:

Class : Class 9
B m kids because Y is only curled much . dont get angry

Ans 13:

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 14:

Class : Class 5
B is the right answer

Ans 15:

Class : Class 9
B is the answer

Ans 16:

Class : Class 10
B

Ans 17:

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 18:

Class : Class 6
b

Ans 19:

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 20:

Class : Class 9
d

Ans 21:

Class : Class 7
B is the answer to this question

Ans 22: (Master Answer)

Class : Class 1

Ans 23:

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:

Class : Class 5
D or B? please vote

Ans 25:

Class : Class 4
sof does not reply that is why we are confused

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Subject :NSO    Class : Class 8

Ans 1:

Class : Class 8
Yes it should be A .

Ans 2:

Class : Class 9
The correct answer is AAAAAAA

Ans 3:

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 4:

Class : Class 8
A

Ans 5:

Class : Class 8
Yes it is A

Ans 6:

Class : Class 10
What is the correct answer A or C ???????

Ans 7:

Class : Class 8
cation(Zn2 ) must be deposited to the cathode.

Ans 8:

Class : Class 8
it should be a

Ans 9:

Class : Class 10
the answer is wrong.....it should be a

Ans 10:

Class : Class 10
thus answer is a

Ans 11:

Class : Class 10

Ans 12:

Class : Class 9
answer A

Ans 13:

Class : Class 5
And for this question must be A

Ans 14:

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 15:

Class : Class 9
It has to be A.

Ans 16:

Class : Class 8
answer is a

Ans 17:

Class : Class 9

Ans 18:

Class : Class 9
Yes the answer is A

Ans 19:

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 20:

Class : Class 8
WWWWRRRROOOONNNNNNNNNNGGGGGGGGGGGGGGGGG

Ans 21:

Class : Class 8
Answer is a

Ans 22:

Class : Class 10
my apologies for the previous explanation answer is : C

Ans 23:

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 24:

Class : Class 8
the answer will be 'A'

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Subject :NSO    Class : Class 3

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Subject :NSO    Class : Class 7

Ans 1:

Class : Class 9
ans is c

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Subject :NSO    Class : Class 7

Ans 1:

Class : Class 9
Plug key is also a type of switch.

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Subject :NSO    Class : Class 5

Ans 1:

Class : Class 5
Ya, filtration can also remove insoluble impurities but in this case sedimentation and decanation is more appropriate answer.

Ans 2:

Class : Class 10
Yes, but in the given figure it is sedimentation

Ans 3:

Class : Class 10
c

Ans 4:

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 5:

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.

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Subject :NSO    Class : Class 7

Ans 1:

Class : Class 9
every single sound has its own secondary waves, so the correct option must be option C.

Ans 2:

Class : Class 7
correct option is c

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Subject :NSO    Class : Class 8

Ans 1:

Class : Class 5

Ans 2:

Class : Class 9

Ans 3:

Class : Class 8
Actually, the solution is opposite to the correct answer

Ans 4:

Class : Class 8

Ans 5:

Class : Class 8

Ans 6:

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 7:

Class : Class 9

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Subject :NSO    Class : Class 8

Ans 1:

Class : Class 9
Supposed to be only ABecause mustard is a non leguminous plantEven it can be rotated with soyabean

Ans 2:

Class : Class 9
Both Wheat and Maize require rotation of crops.

Ans 3:

Class : Class 8
The protein requirement of mustard is fulfilled by the ribozome present in root nodules of soyabean?

Ans 4:

Class : Class 8

Ans 5:

Class : Class 6
yeah right Triguna!!! in both cases soybean is present? why so?

Ans 6:

Class : Class 8
Why so? In both the cases soybean is present.

Ans 7:

Class : Class 8

Ans 8:

Class : Class 8
Think in the way of leguminous crops

Ans 9:

Class : Class 9

Ans 10:

Class : Class 8

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Subject :NSO    Class : Class 6

Ans 1:

Class : Class 7
They didn't give options

Ans 2:

Class : Class 10
NO OPYIONS!

Ans 3:

Class : Class 7
Want option!

Ans 4:

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 5:

Class : Class 6
They did not give options on my ipad .

Ans 6:

Class : Class 7
I typed in c. What is this?

Ans 7:

Class : Class 6
they should be more careful

Ans 8:

Class : Class 6
options are missing

Ans 9:

Class : Class 10
they didn't given on question page so all my friends and I missed that question

Ans 10:

Class : Class 9

Ans 11:

Class : Class 10
no options

Ans 12:

Class : Class 10
iT IS NOT LAPTOP'S MISTAKE IT IS THE WEBSITE'S MISTAKE ITSELF.

Ans 13:

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 14:

Class : Class 9
they didnt give the options

Ans 15:

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 16:

Class : Class 7
my laptop din't provide the options

Ans 17:

Class : Class 6
They're not even giving me options

Ans 18:

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 19:

Class : Class 6
They did not provide options on my laptop but option C is correct.

Ans 20:

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 21:

Class : Class 6
No options

Ans 22:

Class : Class 8
they didn't give the options to my computer

Ans 23:

Class : Class 9

Ans 24:

Class : Class 9
they did not give options

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