2686. Viscosity index of a lubricating oil
is the measure of its flash point.
is the measure of variation of viscosity with temperature.
should be low.
none of these.
✅ The correct answer is option B.
2691. Oxygen required for theoretically complete combustion of 1 Nm³ methane is __________ Nm³.
2
4
6
1
✅ The correct answer is option A.
2697. Blast furnace coke is made from coal by
Low temperature carbonisation
High temperature carbonisation
Medium temperature carbonisation
Heating the coal in an oven in presence of air
✅ The correct answer is option B.
2702. Which of the following processes is used for the production of petroleum coke ?
Stabilisation
Visbreaking
Cracking
Reforming
✅ The correct answer is option C.
2707. Detergent is added as an additive in engine lubricating oil to
reduce deposit formation.
keep contaminants in suspension.
increase oxidation stability.
prevent rusting.
✅ The correct answer is option A.
2712. Efficiency of the combustion of a fuel is judged by the __________ the flue gas.
%of CO₂ in
% of O₂in
Temperature of
Colour of
✅ The correct answer is option B.
2717. Naphtha yield in straight run distillation of crude oil may be about __________ percent.
2
6
12
18
✅ The correct answer is option B.
2722. Deficiency of combustion air during combustion of a gaseous fuel
Lengthens the flame
Causes heat loss of fuel by its partial combustion
Both A & B
Shortens the flame
✅ The correct answer is option C.
2648. Molecular weight of crude oil is in the range of
100-120
230-250
450-550
600-850
✅ The correct answer is option B.
2653. Which of the following is not increased by using preheated combustion air in place of ordinary air at room temperature?
Calorific value of the fuel
Flame temperature achieved
Speed of combustion of fuel
Heat transfer rate to the stock in the furnace
✅ The correct answer is option A.