Fuels and Combustion

Question: In general, the limit of inflammability/explosion limit of fuel gases is widened by the
[A].

increase in gas pressure.

[B].

increase in temperature (i.e. preheating).

[C].

use of pure oxygen for combustion instead of air.

[D].

all (a), (b) & (c).

Answer: Option D

Explanation:

No answer description available for this question.

Question: Explosion limit of blast furnace gas is 37 to 71% gas in gas-air mixture. It means that the blast furnace gas will explode when burnt in a confined space, if its concentration in the gas-air mixture is __________ percent.
[A].

< 37%

[B].

>71%

[C].

in between 37 & 71%

[D].

none of these

Answer: Option C

Explanation:

No answer description available for this question.

Question: Natural draft created by the chimney depends upon
[A].

temperature of the flue gas.

[B].

its height.

[C].

both (a) & (b).

[D].

neither (a) nor (b).

Answer: Option C

Explanation:

No answer description available for this question.

Question: Main constituents of purified Lurgi gas are
[A].

H2, CmHn & CO2

[B].

CO, H2 & CH4

[C].

CO2, O2 & CO

[D].

N2, H2 & CO2

Answer: Option B

Explanation:

No answer description available for this question.

Question: About __________ Nm3 of air will be required for the complete combustion of 2Nm3 of CO.
[A].

2

[B].

3

[C].

5

[D].

1

Answer: Option C

Explanation:

No answer description available for this question.

Question: Flue gas obtained on complete combustion of pure acetylene (a hydrocarbon fuel) will contain
[A].

CO

[B].

CO2

[C].

H2O

[D].

both(b) & (c)

Answer: Option D

Explanation:

No answer description available for this question.

Question: Main component of sewage gas produced during aneorobic decomposition of organic waste (by suitable bacteria) during sewage disposal is
[A].

H2

[B].

CH4

[C].

CO2

[D].

N2

Answer: Option B

Explanation:

No answer description available for this question.

Question: Calorific value of wood gas is about __________ kcal/Nm3.
[A].

1500

[B].

3300

[C].

5400

[D].

8500

Answer: Option B

Explanation:

No answer description available for this question.

Question: Calorific value of gobar gas (containing CH4 = 60% , H2 = 10% ; CO2 = 30%) may be about __________ Kcal/Nm3.
[A].

1800

[B].

3200

[C].

5400

[D].

10200

Answer: Option C

Explanation:

No answer description available for this question.

Question: ‘Wobbe index’ is a characteristic of
[A].

solid fuels

[B].

gaseous fuels

[C].

liquid fuels

[D].

fat coals

Answer: Option B

Explanation:

No answer description available for this question.