Zones of Candle Flame

Q. How does luminous flame differ from non luminous flame?

Q.

Name the various zones of a candle flame. Which zone (or part) of a candle flame is the least hot (or coldest) ?

Q.

Which zone of a candle flame is the hottest ?

Q. The colour of the outermost zone of a candle flame is _________.

1. orange
2. yellow
3. red
4. blue

Q.

In which zone of a candle flame : (a) partial combustion of fuel takes place, and (b) complete combustion of fuel takes place ?

Q. Which of the following is the colour of flame produced by kerosene lamp and LPG stove ?

1. Kerosene lamp - Orange
   LPG stove - Blue
2. Kerosene lamp - Blue
   LPG stove - Orange
3. Kerosene lamp - Yellow
   LPG stove - Blue
4. Kerosene lamp - Blue
   LPG stove - Yellow

Q.

(a) Make a labelled diagram of a candle flame:

(b) What makes the middle zone of a candle flame luminous (or light-giving) ?

Q.

Which of the following are the properties of carbon dioxide?

1. Carbon dioxide is non-combustible.

2. Carbon dioxide is appreciably soluble in water.

3. Carbon dioxide is a stable compound.

4. All of the above

Q.

Which zone of a flame does a goldsmith use for melting gold and silver and why?

Q.

In a candle flame, what is the colour of : (a) innermost zone (b) middle zone, and (c) outer zone ?

Q. The process of hot air rising over cold air is called ___.

Q.

Unburnt carbon particles are present in the

1. blue zone

2. dark inner zone

3. luminous zone

4. non-luminous zone

Q.

The outermost zone of a candle flame is the :

(a) least hot part

(b) coldest part

(c) hottest part

(d) moderately hot part

Q.

The freezer in a refrigerator is located at the top section so that

1. The motor is not heated

2. The heat gained from the environment in high

3. The heat gained from the environment is low

4. The entire chamber of the refrigerator is cooled quickly due to convection

Q. Why does the wick of candle not burn?

Q.

How many zones are there in a flame ?

Q. Smoke in a flame is due to the presence of carbon content in the fuel.

1. True
2. False

Q.

The process of hot air rising over cold air is called

Q. The process of hot air rising over cold air is called ___.

Q. The colour of the outermost zone of a candle flame is _________.

1. orange
2. blue
3. yellow
4. red

Q. Which of the following diagrams shows a non-luminous flame?

1. I only
2. II only
3. I and II
4. II and IV

Q.

Give reason.

A candle brought near the mouth of a jar containing hydrogen gas starts burning but is extinguished when pushed inside the jar.

Q. Which of the following zones of a candle flame produces unburnt carbon particles?​

1. Non-luminous
2. Luminous
3. Outermost
4. Dark

Q. (a) Make a labelled diagram of a candle flame.
(b) Explain each zone of candle flame.

Q. The colour of the outermost zone of a candle flame is _________.

1. blue
2. red
3. orange
4. yellow

Q.

Abida and Ramesh want to heat water taken in separate beakers. Abida kept the beaker near the wick in the yellow part of the candle flame. Ramesh kept the beaker in the outermost part of the flame. Whose water will get heated in a shorter time ? Why ?

Q. Which zone of a flame does a goldsmith use for melting gold and silver and why?

Q. The hottest part of a candle flame is the __________.

1. dark zone
2. luminous zone
3. hot zone
4. non-luminous zone

Q. Molten wax on heating releases __________________.

1. water and carbon dioxide
2. carbon and hydrogen gas
3. carbon dioxide and hydrogen gas
4. water and hydrogen gas

Q. Match Column I with Column II and select the correct option from the codes given below.

	Column I		Column II
(a)	Hottest zone of a candle flame	(i)	Zone of unburnt wax vapours
(b)	Yellow zone of a candle flame	(ii)	Non-luminous zone
(c)	Black innermost zone of the candle flame	(iii)	Incomplete combustion zone

1. (a) - (ii), (b) - (iii), (c) - (i)
2. (a) - (i), (b) - (ii), (c) - (iii)
3. (a) - (ii), (b) - (i), (c) - (iii)
4. (a) - (i), (b) - (iii), (c) - (ii)