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Subject :NSO    Class : Class 8

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Subject :NSO    Class : Class 3

Ans 1:

Class : Class 3
B

Ans 2:

Class : Class 3
B

Ans 3:

Class : Class 5
it is sure sure B

Ans 4:

Class : Class 5
B

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Subject :NSO    Class : Class 3

Ans 1:

Class : Class 3
none of these

Ans 2:

Class : Class 3

Ans 3:

Class : Class 3
C

Ans 4:

Class : Class 4
D

Ans 5:

Class : Class 4
ans is d

Ans 6:

Class : Class 3
D

Ans 7:

Class : Class 5
D non of these

Ans 8:

Class : Class 3
D

Ans 9:

Class : Class 5
ans:D

Ans 10:

Class : Class 3
d

Ans 11:

Class : Class 5
ans:D

Ans 12:

Class : Class 5
ans:D

Ans 13:

Class : Class 5
ans:D

Ans 14:

Class : Class 3
Why answer is not D.

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Subject :NSO    Class : Class 8

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Subject :NSO    Class : Class 8

While demonstrating the reactivity order of different metals, a science teacher arranged the following apparatus :

Select the correct statement regarding this activity.

A A chemical change will take place in all the three beakers if metal Y is magnesium.
B There will be no change in colour of solution if metal Y is aluminium.
C The reactivity order of given metals is Y > Zinc > Iron > Copper if reaction occurs in beaker (III).
D All of these


Ans 1:

Class : Class 8

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Subject :NSO    Class : Class 6

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Subject :NSO    Class : Class 5

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Subject :NSO    Class : Class 5

Ans 1:

Class : Class 7

Ans 2:

Class : Class 5
Correct option should be 1, 3, 2.

Ans 3:

Class : Class 3

Ans 4:

Class : Class 7

Ans 5:

Class : Class 5
(i) Sedimentation - Sedimentation is a physical water purification process using gravity to remove suspended solid impurities from water. The water is allowed to stand till the suspended solid impurities, which are heavier than water, are pulled down by gravity and settle at the bottom of the container.(ii) Chlorination - Chlorination is the process of adding chlorine, or chlorine compounds such as sodium hypochlorite, to drinking water to disinfect it and kill germs. The addition of chlorine will also oxidize any iron, manganese and/or hydrogen sulphide that are present, so that they too can be removed in the filtration process later on.(iii) Filtration - Filtration is a process of water purification, which is used to separate solid impurities from water by using a filter medium that allows the water to pass through but not the solid impurities. These solid impurities are not heavy, so they do not settle at the bottom, but remain suspended. So, a filter is used to trap them.So, to purify water, it must go through sedimentation (i) first, so that heavier and larger size impurities like sand and dirt, are allowed to settle at the bottom of the container and are removed first. Next, water must go through chlorination (ii), so that bacteria and germs present in water are killed. Any iron, manganese and/or hydrogen sulphide, if present, also get oxidized by chlorine. These can be removed later by the filtration (iii) process, along with other suspended impurities.Hence, the right answer is Option D.

Ans 6:

Class : Class 6
the order should be 1-3-2 . there is no option like that. what are these SOF people

Ans 7:

Class : Class 5
correct order is 1-3-2 but there is no option

Ans 8:

Class : Class 6
1-3-2 is the correct order as first we should remove all the insoluble impurities and the the soluble impurities.

Ans 9:

Class : Class 5
The correct order is 1-3-2 and there is no option like that .So,I think that it might be a printing error.

Ans 10:

Class : Class 6

Ans 11:

Class : Class 6
The correct order is 1-3-2 but there's no option having it

Ans 12:

Class : Class 7

Ans 13:

Class : Class 4
the correct order is 1,3,2 but there is no option like that but if you look at option A you'll find the correct order in a descending order (from back) so if there is no option like 1,3,2 then A should be correct

Ans 14:

Class : Class 6

Ans 15:

Class : Class 3

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Subject :NSO    Class : Class 4

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Subject :NSO    Class : Class 5

Ans 1:

Class : Class 6
they all are mammals and give birth to young ones whereas dolphin and whales do not have hairs on their body

Ans 2:

Class : Class 6

Ans 3:

Class : Class 5
All of them don't have hair

Ans 4:

Class : Class 4
it is written not common and then also it's saying D

Ans 5:

Class : Class 5
It’s both b and d

Ans 6:

Class : Class 6
bat has microscopic hair, bear has fur, dolphin has hair when it is a baby, platypus has hair. platypus also lays eggs. so d is the answer

Ans 7:

Class : Class 6
platypus lays eggs! Go search it on google

Ans 8:

Class : Class 6
It is written not common then how will the ans be D

Ans 9:

Class : Class 6
In platypus they lay eggs

Ans 10:

Class : Class 5
it should be both B and D

Ans 11:

Class : Class 4
Both B and D are correct

Ans 12:

Class : Class 6
Why will the answer be D? The animals are dolphin, whale, bat, bear and platypus, and they are all mammals and give birth to young ones. This is a common feature, but the question says to mention the uncommon feature. The answer should be C for sure. The solution given is wrong.

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