National Science Olympiad Forum By SOF Olympiad Trainer - Page 673

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Subject :NSO    Class : Class 9

Ans 1:

Class : Class 9
Can u pls send the method

Ans 2:

Class : Class 9
9.6

Ans 3:

Class : Class 10

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Subject :NSO    Class : Class 9

Ans 1:

Class : Class 10
the answer is 12 cm

Ans 2:

Class : Class 9
The answer is 12cm

Ans 3:

Class : Class 9
The answer is 12cm

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Subject :NSO    Class : Class 8

Ans 1:

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

Ans 2:

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:

Class : Class 8
Plastic is unable to be charged.. Wrong answer!

Ans 4:

Class : Class 8
positive charge is acqired

Ans 5:

Class : Class 4

Ans 6:

Class : Class 8
Answer is A... positive charge is acquire by the glass rod

Ans 7:

Class : Class 6

Ans 8:

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 9:

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.

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Subject :NSO    Class : Class 8

Ans 1:

Class : Class 10

Ans 2:

Class : Class 5
Why

Ans 3: (Master Answer)

Class : Class 1
The correct answer is C.

Ans 4:

Class : Class 10

Ans 5:

Class : Class 10
Protons don't move.

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Subject :NSO    Class : Class 5

Ans 1:

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

Ans 2:

Class : Class 5
D

Ans 3:

Class : Class 5
D

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Subject :NSO    Class : Class 4

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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 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 2:

Class : Class 5
B is the right answer

Ans 3:

Class : Class 7
B is the answer to this question

Ans 4:

Class : Class 5
D or B? please vote

Ans 5:

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

Ans 6:

Class : Class 5
B is the correct answer

Ans 7:

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

Ans 8:

Class : Class 3
b

Ans 9:

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 10:

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

Ans 11:

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 12:

Class : Class 5
cONFUSED IN d AND B

Ans 13:

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 14:

Class : Class 5
b as Y expands more

Ans 15:

Class : Class 9
d

Ans 16:

Class : Class 6
b

Ans 17:

Class : Class 8
D or B not sure.

Ans 18:

Class : Class 5
C is the correct answer

Ans 19:

Class : Class 10
B

Ans 20:

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 21: (Master Answer)

Class : Class 1

Ans 22:

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 23:

Class : Class 9
B is the answer

Ans 24:

Class : Class 3

Ans 25:

Class : Class 8
The answer should be opt.B

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Subject :NSO    Class : Class 8

Ans 1:

Class : Class 8
answer is a

Ans 2:

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

Ans 3:

Class : Class 8
Answer is a

Ans 4:

Class : Class 8
WWWWRRRROOOONNNNNNNNNNGGGGGGGGGGGGGGGGG

Ans 5:

Class : Class 8
Yes it is A

Ans 6:

Class : Class 9
It has to be A.

Ans 7:

Class : Class 8
the answer will be 'A'

Ans 8:

Class : Class 8
A

Ans 9:

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

Ans 10:

Class : Class 5
And for this question must be A

Ans 11:

Class : Class 10
thus answer is a

Ans 12:

Class : Class 9
Yes the answer is A

Ans 13:

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 14:

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

Ans 15:

Class : Class 9
The correct answer is AAAAAAA

Ans 16:

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 17:

Class : Class 8
it should be a

Ans 18:

Class : Class 10

Ans 19:

Class : Class 9

Ans 20:

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

Ans 21:

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 22:

Class : Class 9
answer A

Ans 23:

Class : Class 8
Yes it should be A .

Ans 24:

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?

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Subject :NSO    Class : Class 3

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