National Science Olympiad Forum By SOF Olympiad Trainer - Page 663

User Forum

Subject :NSO    Class : Class 9

Ans 1:

Class : Class 9
pay attention to sum of their digits

Ans 2: (Master Answer)

Class : Class 1
The correct answer is B.

Post Your Answer

Subject :NSO    Class : Class 9

Ans 1:

Class : Class 10

Ans 2:

Class : Class 9
Can u pls send the method

Ans 3:

Class : Class 9
9.6

Post Your Answer

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

Post Your Answer

Subject :NSO    Class : Class 8

Ans 1:

Class : Class 6

Ans 2:

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

Ans 3:

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

Ans 4:

Class : Class 4

Ans 5:

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.

Ans 6:

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

Ans 7:

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 8:

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 9:

Class : Class 8
positive charge is acqired

Post Your Answer

Subject :NSO    Class : Class 8

Ans 1:

Class : Class 10

Ans 2:

Class : Class 5
Why

Ans 3:

Class : Class 10

Ans 4:

Class : Class 10
Protons don't move.

Ans 5: (Master Answer)

Class : Class 1
The correct answer is C.

Post Your Answer

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

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 9
d

Ans 2:

Class : Class 8
The answer should be opt.B

Ans 3:

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

Ans 4:

Class : Class 5
B is the right answer

Ans 5:

Class : Class 5
D or B? please vote

Ans 6: (Master Answer)

Class : Class 1

Ans 7:

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 8:

Class : Class 9
B is the answer

Ans 9:

Class : Class 8
D or B not sure.

Ans 10:

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 11:

Class : Class 3
b

Ans 12:

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 13:

Class : Class 3

Ans 14:

Class : Class 6
b

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 5
C is the correct answer

Ans 17:

Class : Class 5
B is the correct answer

Ans 18:

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 19:

Class : Class 10
B

Ans 20:

Class : Class 5
b as Y expands more

Ans 21:

Class : Class 7
B is the answer to this question

Ans 22:

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 23:

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

Ans 24:

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

Ans 25:

Class : Class 5
cONFUSED IN d AND B

Post Your Answer

Subject :NSO    Class : Class 8

Ans 1:

Class : Class 8
the answer will be 'A'

Ans 2:

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 3:

Class : Class 5
And for this question must be A

Ans 4:

Class : Class 8
Yes it should be A .

Ans 5:

Class : Class 8
A

Ans 6:

Class : Class 9
The correct answer is AAAAAAA

Ans 7:

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

Ans 8:

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 9:

Class : Class 9
answer A

Ans 10:

Class : Class 9
It has to be A.

Ans 11:

Class : Class 8
Yes it is A

Ans 12:

Class : Class 10
thus answer is a

Ans 13:

Class : Class 8
Answer is a

Ans 14:

Class : Class 10

Ans 15:

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

Ans 16:

Class : Class 8
it should be a

Ans 17:

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 18:

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 19:

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

Ans 20:

Class : Class 8
answer is a

Ans 21:

Class : Class 9

Ans 22:

Class : Class 8
WWWWRRRROOOONNNNNNNNNNGGGGGGGGGGGGGGGGG

Ans 23:

Class : Class 9
Yes the answer is A

Ans 24:

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

Post Your Answer