Question: Coal is heated in presence of air to a temperature of about _______________ °C, while determining its ash content for proximate analysis?

• 1. 500
• 2. 750
• 3. 950
• 4. 1100

Question: Higher percentage of ash in coal meant for the production of metallurgical grade coke ___________________?

• 1. Decreases the hardness of coke
• 2. Decreases the abrasion resistance of coke
• 3. Causes brittleness in steel
• 4. None of these

Question: Eschka mixture, which is used for the determination of sulphur in coal, is a mixture of _____________________?

• 1. MgO & Na2CO3
• 2. MgSO4 & BaCl2
• 3. BaSO4 & NaCl
• 4. MgCO3 & NaCl

Question: Ignition temperature of a fuel in air is ______________ that in pure oxygen?

• 1. More than
• 2. Less than
• 3. Equal to
• 4. Either more or less; depends on the type of fuel

Question: Which of the following gaseous fuels has the lowest calorific value ?

• 1. Gobar gas
• 2. Refinery gas
• 3. Converter gas
• 4. Blast furnace gas

Question: Turndown ratio of a gas burner is equal to the __________________ ?

• 1. Maximum to minimum heat input ratio
• 2. Maximum to minimum permissible gas flow rate
• 3. Both A & B
• 4. Minimum to maximum heat input ratio

Question: Which of the following has the least calorific value (kcal/Nm3) ?

• 1. Blast furnace gas
• 2. Coke oven gas
• 3. Sewage gas
• 4. Natural gas

Question: Carbon Content by weight in air dried wood may be about _______________ percent?

• 1. 10
• 2. 25
• 3. 50
• 4. 80

Question: Pick the odd man out?

• 1. Briquettes
• 2. Wood
• 3. Oil gas
• 4. Pitch creosote mixture

Question: Pick out the wrong statement ?

• 1. High concentration of oxygen in flue gas means high stack loss
• 2. Gaseous fuels require the least % excess air for complete combustion
• 3. The ratio of fixed carbon to volatile matter percentage in coal is called its ‘fuel ratio’
• 4. Calorific value of natural gas is more than that of LPG