National Science Olympiad Forum By SOF Olympiad Trainer - Page 679

User Forum

Subject :NSO    Class : Class 5

Ans 1:

Class : Class 5
D

Ans 2:

Class : Class 5
D

Ans 3:

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

Post Your Answer

Subject :NSO    Class : Class 4

Post Your Answer

Subject :NSO    Class : Class 10

Ans 1: (Master Answer)

Class : Class 1
The correct answer is D.

Post Your Answer

Subject :NSO    Class : Class 5

Ans 1:

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 2:

Class : Class 5
cONFUSED IN d AND B

Ans 3:

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

Ans 4:

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

Ans 5:

Class : Class 5
B is the right answer

Ans 6:

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 7:

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

Ans 8:

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 9:

Class : Class 9
B is the answer

Ans 10: (Master Answer)

Class : Class 1

Ans 11:

Class : Class 5
C is the correct answer

Ans 12:

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 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 3

Ans 15:

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 16:

Class : Class 6
b

Ans 17:

Class : Class 7
B is the answer to this question

Ans 18:

Class : Class 5
b as Y expands more

Ans 19:

Class : Class 9
d

Ans 20:

Class : Class 8
The answer should be opt.B

Ans 21:

Class : Class 10
B

Ans 22:

Class : Class 5
D or B? please vote

Ans 23:

Class : Class 5
B is the correct answer

Ans 24:

Class : Class 8
D or B not sure.

Ans 25:

Class : Class 3
b

Post Your Answer

Subject :NSO    Class : Class 8

Ans 1:

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

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 9

Ans 4:

Class : Class 8
answer is a

Ans 5:

Class : Class 9
It has to be A.

Ans 6:

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:

Class : Class 10
thus answer is a

Ans 8:

Class : Class 10

Ans 9:

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 10:

Class : Class 8
Yes it is A

Ans 11:

Class : Class 8
WWWWRRRROOOONNNNNNNNNNGGGGGGGGGGGGGGGGG

Ans 12:

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

Ans 13:

Class : Class 5
And for this question must be A

Ans 14:

Class : Class 9
answer A

Ans 15:

Class : Class 8
Answer is a

Ans 16:

Class : Class 8
it should be a

Ans 17:

Class : Class 9
Yes the answer is A

Ans 18:

Class : Class 8
A

Ans 19:

Class : Class 8
the answer will be 'A'

Ans 20:

Class : Class 9
The correct answer is AAAAAAA

Ans 21:

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

Ans 22:

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 23:

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

Ans 24:

Class : Class 8
Yes it should be A .

Post Your Answer

Subject :NSO    Class : Class 3

Post Your Answer

Subject :NSO    Class : Class 7

Ans 1:

Class : Class 9
ans is c

Post Your Answer

Subject :NSO    Class : Class 7

Ans 1:

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

Post Your Answer

Subject :NSO    Class : Class 5

Ans 1:

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 2:

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

Ans 3:

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 4:

Class : Class 10
c

Ans 5:

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

Post Your Answer

Subject :NSO    Class : Class 7

Ans 1:

Class : Class 7
correct option is c

Ans 2:

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

Post Your Answer