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Subject :NSO    Class : Class 7

The steps of wastewater treatment plant are given below randomly.
(i) Wastewater is passed into sedimentation tank.
(ii) Sludge is decomposed by anaerobic bacteria.
(iii) Wastewater is passed through bar screens.
(iv) Wastewater is passed to grit and sand removal tank.
(v) Solids settle at the bottom and floatable materials are removed by skimmer.
(vi) Aeration of water takes place.
(vii) Disinfection of water by adding chlorine.
Which of the following represents correct sequence of steps?

A (iii) → (iv) → (i) → (v) → (ii) → (vi) → (vii)
B (iv) → (iii) → (i) → (v) → (ii) → (vi) → (vii)
C (iii) → (iv) → (v) → (i) → (ii) → (vi) → (vii)
D (iii) → (iv) → (i) → (ii) → (v) → (vi) → (vii)


Ans 1:

Class : Class 7
A

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Subject :NSO    Class : Class 5

Ans 1:

Class : Class 5

Ans 2:

Class : Class 5
D

Ans 3:

Class : Class 6
They are pointing to the stem and the answer is about roots🧐🤔

Ans 4:

Class : Class 5
The answer is D as X is labeled as stem but the answer is given for root.

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Subject :NSO    Class : Class 5

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Subject :NSO    Class : Class 5

Which of the following damages are associated with acid rain?
(i) Erosion of stone statues and buildings
(ii) Melting of ice caps
(iii) Increase in the number of mosquitoes
(iv) Threat to the life of aquatic beings
(v) Loss of soil fertility.

A(i), (ii) and (iii) only
B(i), (iv) and (v) only
C(i) and (iii) only
D(ii), (iii) and (v) only


In the solution, it says that the melting of ice caps is an incorrect option, but why? Acid rain is nothing but industrial chemicals that react with water vapour in the air and precipitate in form of hail, snow or rain and is acidic to nature. So in the poles, this acid can fall as snow, so they can melt the ice sheets, right? Please explain this question.

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Subject :NSO    Class : Class 6

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Subject :NSO    Class : Class 8

Different zones of a candle flame are marked by the letters P, Q, R and S.

Which of the following statements are correct?
(i) P is the luminous zone and is the hottest part of candle flame.
(ii) In zone Q, there is inadequate supply of oxygen.
(iii) Zone R contains unburnt wax vapours produced by melting of wax.
(iv) In S zone, carbon monoxide burns with a blue flame.

A (i) and (ii) only
B (ii), (iii) and (iv) only
C (ii) and (iv) only
D (i), (ii) and (iii) only


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Subject :NSO    Class : Class 8

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Subject :NSO    Class : Class 8

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Subject :NSO    Class : Class 8

Ans 1:

Class : Class 8
Child's play though. calorific value=heat/unit mass of the fuel burnt =180,000/4.5 =40000 kJ/kg it is a question from our very own NCERT TEXTBOOK.

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Subject :NSO    Class : Class 8

Ans 1:

Class : Class 8
Sulfur dioxide and chlorine are not produced because CNG is composed of methane. The fact that it produces large amount of carbon dioxide is not helpful or advantageous by any means. Whether it is used in compressed form or not does not make it eco-friendly; but, yes, it produces no smoke SPM upon combustion. So correct answer is (B).

Ans 2:

Class : Class 9
totally wrong

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