National Science Olympiad Forum By SOF Olympiad Trainer - Page 646

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Subject :NSO    Class : Class 5

Ans 1:

Class : Class 5
D

Ans 2:

Class : Class 8
It should be option C. It should be discouraged.

Ans 3:

Class : Class 5
D

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Subject :NSO    Class : Class 4

Ans 1:

Class : Class 4
B

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Subject :NSO    Class : Class 10

Ans 1: (Master Answer)

Class : Class 1
The correct answer is D.

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Subject :NSO    Class : Class 5

Ans 1:

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 2:

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 3:

Class : Class 5
B is the right answer

Ans 4:

Class : Class 9
B is the answer

Ans 5:

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 6:

Class : Class 8
D or B not sure.

Ans 7:

Class : Class 3
b

Ans 8:

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 9:

Class : Class 6
b

Ans 10:

Class : Class 5
C is the correct answer

Ans 11:

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

Ans 12: (Master Answer)

Class : Class 1

Ans 13:

Class : Class 8
The answer should be opt.B

Ans 14:

Class : Class 5
cONFUSED IN d AND B

Ans 15:

Class : Class 3

Ans 16:

Class : Class 5
B is the correct answer

Ans 17:

Class : Class 5
D or B? please vote

Ans 18:

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 19:

Class : Class 7
B is the answer to this question

Ans 20:

Class : Class 10
B

Ans 21:

Class : Class 5
b as Y expands more

Ans 22:

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

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 9
d

Ans 25:

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

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Subject :NSO    Class : Class 8

Ans 1:

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

Ans 2:

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 3:

Class : Class 10

Ans 4:

Class : Class 9
Yes the answer is A

Ans 5:

Class : Class 8
answer is a

Ans 6:

Class : Class 8
Answer is a

Ans 7:

Class : Class 8
Yes it should be A .

Ans 8:

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

Ans 9:

Class : Class 8
A

Ans 10:

Class : Class 5
And for this question must be A

Ans 11:

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 12:

Class : Class 9
answer A

Ans 13:

Class : Class 9
The correct answer is AAAAAAA

Ans 14:

Class : Class 8
it should be a

Ans 15:

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 16:

Class : Class 8
WWWWRRRROOOONNNNNNNNNNGGGGGGGGGGGGGGGGG

Ans 17:

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

Ans 18:

Class : Class 9
It has to be A.

Ans 19:

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:

Class : Class 8
the answer will be 'A'

Ans 21:

Class : Class 8
Yes it is A

Ans 22:

Class : Class 10
thus answer is a

Ans 23:

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

Ans 24:

Class : Class 9

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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 10
Yes, but in the given figure it is sedimentation

Ans 2:

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 3:

Class : Class 10
c

Ans 4:

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:

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

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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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