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.

Incomplete combustion of fuel in the furnace is judged by high __________ of the flue gases.

A. CO content

B. Dew point

C. CO₂ content

D. O₂ content

High sulphur content in a fuel __________ of the flue gases.

A. Decreases the dew point

B. Increases the dew point

C. Reduces the combustion efficiency by limiting the permissible temperature reduction

D. Both B & C

Fusion point of coal ash generally varies from 1000 to 1700°C. Ash having fusion point less than __________ °C is liable to form clinker.

A. 1100

B. 1250

C. 1350

D. 1400

Coal tar fuel - 200 (CTF 200) is a mixture of

A. Pitch and creosote oil

B. Light oil and pitch

C. Anthracene and crecosote oil

D. Solar oil and pitch