Smoke

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

1. Outer zone (blue)
2. Middle zone (yellow)
3. Innermost zone (black)
4. Gold and silver cant be melted

Q. when we burn cotton dipped in ghee ( diya) what type of gase is released?

Q.

Name two gases which burn with a blue flame.

Q. Does fire have any mass?

Q.

Why does petrol catch fire?

Q.

What is flame ?where is it used ?

Q.

Whenever there is a flame, smoke will surely be produced.

1. False

2. True

Q.

Coke is used to make shoe polish.

1. True
2. False

Q.

Name an element that burns in air with a bright blue flame.

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

1. True
2. False

Q.

The zone that produces light in a candle flame is called

Q. Question 13
Abida and Ramesh were doing an experiment in which water was to be heated in a beaker. Abidakept 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 waterwill get heated in a shorter time?

Q. When you tilt a burning candle, the flame will ___ .

1. None of these
2. tilt to the side
3. stay upright
4. either stay upright or tilt to the side

Q. determines the direction and shape of the flame.

1. Temperature
2. Surroundings
3. Gravity
4. Surface area

Q. The combination of smoke and fog is called _____.

1. soot
2. mist
3. dust
4. smog

Q. Flickering and tear drop shape of flame is due to .

1. condensation
2. evaporation
3. convection
4. diffusion

Q. When you heat wood to 540 degree Celsius in the absence of oxygen, will be formed.

1. lignite
2. charcoal
3. peat
4. coal tar

Q. determines the direction and shape of the flame.

1. Temperature
2. Surroundings
3. Gravity
4. Surface area

Q. Which of the following non-metal is useful as a rocket fuel?

1. $Cl$
2. $H_2$
3. $S$
4. $N_2$

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

1. Middle zone (yellow)
2. Gold and silver cant be melted
3. Innermost zone (black)
4. Outer zone (blue)

Q.

All flames produce smoke.

1. Only Statement-1 is True

2. Only Statement-2 is True

Q. Smoke appears when compound is present in the fuel.

1. involatile
2. volatile
3. acidic
4. basic

Q. Gita, Vineeta and Suneeta were doing an experiment in which water was to be heated in a 10 ml conical flask. Gita kept the flask near the wick in the innermost part of the candle flame. Vineeta kept the flask in the middle part of the flame. Suneeta kept the flask in the outermost part of the flame. Whose water will get heated in a shorter time?

1. Gita
2. Suneeta
3. Vineeta
4. Water will get heated with same rate for all of them.

Q.

Incomplete burning might take place when -

1. Charcoal has no volatile compounds in it.

2. Charcoal is black.

3. Charcoal is artificially made.

4. Charcoal is a gaseous fuel.

Q. A paper-wrapped tightly around the joint of a brass tube and its wooden handle is put in a flame, the paper will:

1. not burn at any place
2. burn around the wooden handle
3. catch fire immediately
4. burn around the brass tube

Q. Flickering and tear drop shape of flame is due to .

1. condensation
2. evaporation
3. convection
4. diffusion

Q.

In a candle, the process of burning continues because:

1. The wick keeps delivering molten wax to the flame.

2. The wick keeps burning.

3. Solid wax keeps burning.

4. Sufficient heat energy is available.

Q. What we are not able to burn a piece of wet paper?

Q.

Which of the following substance in combination with fog makes smog?

1. Water

2. Sound

3. Smoke

4. Sand

Q.

When does a fire produce smoke?

1. Always.

2. During incomplete combustion.

3. During complete combustion.

4. When large amout of substance is burned.