C.N.G. and L.P.G. burn with sooty flame
  • a)
    True
  • b)
    False
Correct answer is option 'A'. Can you explain this answer?

Rajbala answered  •  4 hours ago
They burn produced blue flame ,so they burn with a sooty flame.The blue is called "chemoluminescence". It's the light produced directly by the combustion reaction, and will therefore be present during most hydrocarbon fires. The yellow and orange (which provide most of the light from the actual fire) come from a more interesting source. When hydrocarbons burn without sufficient oxygen mixed in, they burn incompletely. This reaction produces tiny particles of solid carbon, which we generally refer to as 'soot'. The flame is full of this finely dispersed carbon, which gets heated by the combustion. A typical wood fire produces flames anywhere from 1000 K to 2000 K. At that temperature, the particles glow, giving off orange to yellow light. Those tiny bits of superhot carbon is what causes most of the light we see from fires.
Gas burners are generally designed to mix plenty of air in with the gas before it burns. so that incomplete combustion doesn't happen, soot doesn't get produced, and so all you see is the blue from the combustion. But if you block some of the air from getting into the burners, you'll find that gas flames burn just as yellow as wood.

The moist bread becomes mouldy after a few days when it is left in a container with a cover. Which of the following conditions favour the growth of the fungus?
  • a)
    Absence of water
  • b)
    Absence of light
  • c)
    Presence of sunlight
  • d)
    Presence of carbon dioxide
Correct answer is option 'B'. Can you explain this answer?

Amarjit Singh answered  •  4 hours ago
If a piece of bread is kept in a container in a moist place for two to three days, some light type of hairy growth may happen on the surface. It is generally referred to as the bread mold. It is a kind of fungus. The absence of light and moist temperature favour the growth of the fungus.

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Harini Pragalathan answered  •  4 hours ago
The process of heating of coal in the absence of air is called as destructive distillation of coal. The products obtained on destructive distillation of coal are coke, coal gas, coal tar, and ammoniacal liquor.

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Harini Pragalathan answered  •  4 hours ago
Chromosomes are thread-like molecules that carry hereditary from height to eye colour. They are made of protein and one molecule of DNA, which contains an organism's genetic instructions, passed down from parents.

The value of x in the following figure is
  • a)
    100o
  • b)
    90o
  • c)
    72o
  • d)
    120o
Correct answer is option 'C'. Can you explain this answer?

Aasim Shaikh answered  •  7 hours ago
The correct option is c because the sum of each angle of pentagon is 360 and the pentagon has 5 side so
360/5=72

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Aasim Shaikh answered  •  7 hours ago
Its functions are The nucleus provides a site for genetictranscription that is segregated from the location of translation in the cytoplasm, allowing levels of gene regulation that are not available to prokaryotes. The main function of the cell nucleus is to control gene expression and mediate the replication of DNA during thecell cycle.

The nucleus is an organelle found in eukaryotic c
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Aasim Shaikh answered  •  7 hours ago
1.respect and care for all forms of life
2.improve the quality of human life
3.conserve the earth's vitality and diversity

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Harini Pragalathan answered  •  9 hours ago
The white rulers were chiefly traders. Their chief aim was to make profits at all cost. Hence, they began to ruin the Indian industries.

Salt is spread on pavement snow during winter in cold countries?

Harini Pragalathan answered  •  9 hours ago
The reason why salt is spread on pavement snow during winter in cold countries is because this practice lowers the freezing point of the water that forms the ice which makes the ice melt and prevents snow to collect on the pavements.

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Harini Pragalathan answered  •  9 hours ago
A stereotype is a mistaken idea or belief many people have about a thing or group that is based upon how they look on the outside, which may be untrue or only partly true. Stereotyping people is a type of prejudice because what is on the outside is a small part of which a person is.

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Kalpana Friends answered  •  9 hours ago
Human resources include the people of a country involved in various profession. Human posses knowledge, social and personal attributes, creativity, competencies and the ability to work in order to produce goods of economic value. Humans are the most important resources they are instrumental in the best utilisation of natural resources

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Kalpana Friends answered  •  9 hours ago
Actual resources are the ones which are being utilised by humans. The rich coal deposit found in the Appalachian regions of eastern USA and the mineral oil deposits of West Asia are examples of actual resources.

potential resources are the ones which are not being used by humans at present but have the potential of providing great benefits if use. Sunlight has the potential for meeting
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