Fuel and Combustion MCQs

371. Calorific value as determined by bomb calorimeter is the

Higher calorific value at constant volume

Gross calorific value at constant pressure

Lower calorific value at constant pressure

Net calorific value at constant volume

✅ The correct answer is option A.

372. Coke oven gas after passing through return electrostatic tar precipitator (RETP) is used for the

Hot scarfing of steel slabs

Mixing with blast furnace gas

Coke oven battery heating

Steel ladle drying

✅ The correct answer is option C.

373. In high temperature carbonisation (as compared to low temperature carbonisation) of coal

Coke oven gas yield is more

Tar yield is less but free carbon in tar is more

Calorific value of coke oven gas is less

All of the above

✅ The correct answer is option D.

374. Which of the following is not a manufactured fuel ?

Furnace oil

Bagasse

Semi-coke

Kerosene

✅ The correct answer is option B.

375. Kopper-Totzek coal gasifier (installed in a coal based nitrogeneous fertiliser plant) employs a/an __________ bed gasifier.

Entrained

Moving

Fixed

Fluidised

✅ The correct answer is option A.

376. Which of the following is not a by-product fuel?

Producer gas

Blast furnace gas

Coke oven gas

Refinery gas

✅ The correct answer is option A.

377. A good metallurgical coke

Should have high porosity

Should be brittle

Must contain moderate quantities of ash, moisture, sulphur and volatile matters

Should have low fusion point of its ash

✅ The correct answer is option A.

378. Steam is intermittently admitted into the fuel bed during the production of producer gas to

Convert CO to CO₂

Increase the combustion rate

Increase the gas production rate

Minimise the chances of clinker formation

✅ The correct answer is option D.

379. The average molecular weight of a flue gas having the composition by volume as CO₂ = 25%, O₂ = 25%, N₂ = 50% will be

27.6

23

47.3

42.9

✅ The correct answer is option B.

380. The calorific value of L.D. converter gas is about __________ Kcal/Nm³ .

1800

800

4500

10000

✅ The correct answer is option A.