Beehive coke oven________________?

A. Facilitates by-products recovery
B. Takes 2-3 days for coking of coal but requires no external fuel for heating
C. Gives larger yield of coke (around 85%) as compared to by-product ovens
D. Produces coke with very poor strength

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

A. 500
B. 750
C. 950
D. 1100

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

A. Decreases the hardness of coke
B. Decreases the abrasion resistance of coke
C. Causes brittleness in steel
D. None of these

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

A. MgO & Na2CO3
B. MgSO4 & BaCl2
C. BaSO4 & NaCl
D. MgCO3 & NaCl

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

A. More than
B. Less than
C. Equal to
D. Either more or less; depends on the type of fuel

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

A. Gobar gas
B. Refinery gas
C. Converter gas
D. Blast furnace gas

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

A. Maximum to minimum heat input ratio
B. Maximum to minimum permissible gas flow rate
C. Both A. & B.
D. Minimum to maximum heat input ratio

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

A. Blast furnace gas
B. Coke oven gas
C. Sewage gas
D. Natural gas

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

A. 10
B. 25
C. 50
D. 80