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Ayushree Barman from Sri Sri Academy, Kolkata
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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Ankit Hazarika from IVWS, Kolkata
Subject :NSO    Class : Class 6

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arnav from the gurukul, Panchkula
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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arnav from the gurukul, Panchkula
Subject :NSO    Class : Class 8

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arnav from the gurukul, Panchkula
Subject :NSO    Class : Class 8

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arnav from the gurukul, Panchkula
Subject :NSO    Class : Class 8

Ans 1:

Saranyaa Adak from Delhi Public School, Durgapur
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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arnav from the gurukul, Panchkula
Subject :NSO    Class : Class 8

Ans 1:

PARTH JAIN from DPS INDIRAPURAM, GHAZIABAD
Class : Class 8

Ans 2:

Saranyaa Adak from Delhi Public School, Durgapur
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 3:

ARNAB MANDAL from NAVY CHILDREN SCHOOL, VIZAG
Class : Class 9
totally wrong

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Kriday from KDAV, Jamnagar
Subject :NSO    Class : Class 8

Which of the following are possible advantages of using bacteria in sewage treatment?
(i) Bacteria multiply quickly, thus producing a cheap and abundant source of enzymes.
(ii) Only one type of bacteria is required to provide the various enzymes necessary for different kinds of wastes.
(iii) Bacteria can break down waste under anaerobic or aerobic condition.

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


is only one kind of bacteria required to provide the various enzymes necessary for different kinds of wastes?because it was given so in the summary but in the solution it is showing this statement as false

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Agustya vaid from Somerville school vasundhara enclave, Delhi
Subject :NSO    Class : Class 6

Manisha took some vinegar in a test tube and added some baking powder to it. Then she lit a matchstick and brought it near the mouth of the test tube. The flame of matchstick got extinguished.
Which of the following is correct conclusion regarding the given experiment?

A Carbon dioxide gas does not support burning.
B Air contains carbon dioxide.
C Oxygen gas present in the air is necessary for burning.
D Oxygen gas can extinguish fire.


Ans 1:

Shriya from VIBGYOR High, Bangalore
Class : Class 6
A: Carbon dioxide gas does not support burning.

Ans 2:

Hitarth from Mushtifund High School , Goa
Class : Class 6
A

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Agustya vaid from Somerville school vasundhara enclave, Delhi
Subject :NSO    Class : Class 6

Raveena covered a beaker of boiled water with a metal tray as shown in the diagram.

The beaker and metal tray were then removed from the tripod stand and left on the table. After two minutes, which of the following can be observed?

A Water droplets are seen on the outer part of metal tray.
B Water droplets are seen on the inner part of tray and inner part of the beaker.
C Water droplets are seen on the inner part of metal tray and outer part of the beaker.
D Water droplets are seen on the outer part of beaker only.


Ans 1:

SKIyer from CNS, Mumbai
Class : Class 6
B, anybody marking something else is mad.

Ans 2:

archit from st Joseph's school, sonedhadra
Class : Class 5
B

Ans 3:

tanmay chaudhry from BAL BHAVAN PUBLIC SCHOOL, New Delhi
Class : Class 4
answer is b

Ans 4:

Agustya vaid from Somerville school vasundhara enclave, Delhi
Class : Class 7
yeahhhhhhhhhhhhhhhhhhhhhhhhhhhhhh

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