Fuels and Combustion

Question: Gobar gas is produced by the __________ of ‘gobar’ (cow dung).
[A].

hydrolysis

[B].

fermentation

[C].

oxidation

[D].

dehydration

Answer: Option B

Explanation:

No answer description available for this question.

Question: __________ has the widest inflammability limit (explosion limit) of all the gases.
[A].

Hydrogen

[B].

Carbon monoxide

[C].

Acetylene

[D].

Methane

Answer: Option C

Explanation:

No answer description available for this question.

Question: Combustion reaction of fuels is a/an __________ reaction.
[A].

auto catalytic

[B].

exothermic

[C].

endothermic

[D].

none of these

Answer: Option B

Explanation:

No answer description available for this question.

Question: In low temperature carbonisation of coal, the
[A].

yield of coke oven gas is 290 Nm3 /ton dry coal.

[B].

volatile matter in coke is zero.

[C].

temperature maintained is 700°C.

[D].

yield of tar is about 3% of dry coal.

Answer: Option C

Explanation:

No answer description available for this question.

Question: Bulk density of pulverised coal may be about __________ kg/m3.
[A].

100

[B].

500

[C].

1000

[D].

1500

Answer: Option B

Explanation:

No answer description available for this question.

Question: ‘Fat coals’ are those coals which have very high
[A].

caking capacity.

[B].

volatile matter content.

[C].

fusion point of its ash.

[D].

inherent moisture content.

Answer: Option A

Explanation:

No answer description available for this question.

Question: Caking index of coal blend used for blast furnace coke making is about
[A].

8

[B].

12

[C].

22

[D].

36

Answer: Option C

Explanation:

No answer description available for this question.

Question: During combustion of coal on grate, clinker formation is increased by the
[A].

use of thick fire bed.

[B].

low fusion point of ash (< 1100° C).

[C].

use of preheated primary air.

[D].

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

Answer: Option D

Explanation:

No answer description available for this question.

Question: Mineral matter content (M) and ash content (A) in coal are approximately related as
[A].

M = 1.1A

[B].

M = A

[C].

M = 1.5A

[D].

M = 2A

Answer: Option A

Explanation:

No answer description available for this question.

Question: Low temperature oxidation of coal is accelerated by the
[A].

storage in large heaps.

[B].

storage in compressed piles.

[C].

absence of porous or friable particles.

[D].

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

Answer: Option A

Explanation:

No answer description available for this question.