11. 

(a) Coal gas
(b) Oil gas
(c) Natural gas
(d) Producer gas

Answer: (c)

12. Which of the following are the properties of CNG?
1. It ignites at a higher temperature
2. The conversion is very easy
3. The operating cost is much lower
4. Combustion of this gas leads to more 𝐶𝐶𝐶 emission
5. Emission contain no unregulated pollutants

(a) 1, 2, 3 and 4 only
(b) 1, 3, 4 and 5 only
(c) 1, 2, 3 and 5 only
(d) 2, 3, 4 and 5 only

Answer: (c)

13. Consider the following steps for manufacturing of coal gas:
1. The gas is scrubbed by passing through a hydraulic main
2. Coal is carbonized in absence of air about 1300°𝐶
3. Tar and ammonia, present in the gas are removed by scrubbing with water in a scrubber
4. Tar is removed by cooling the gas in a huge water cooled heat exchanger called condenser
5. The gas is freed from hydrogen sulphide by passing it over moist ferric oxide, contained in a purifier
6. The cooled gas is then scrubbed with creosote oil which dissolves benzol and naphthalene

What is the correct sequence of steps occurred?
(a) 2, 1, 4, 3, 6 and 5
(b) 1, 2, 4, 3, 5 and 6
(c) 1, 2, 3, 4, 5 and 6
(d) 2, 3, 1, 3, 6 and 5

Answer: (a)

14. Consider the following reaction:
Which one of the following gas can be manufactured by above reaction?
(a) Coal gas
(b) Water gas
(c) Producer gas
(d) Oil gas

Answer: (d)

15. Consider the following zones for the production reaction of producer gas:
1. Ash zone
2. Reduction zone
3. Distillation zone
4. Combustion zone

What is the correct sequence of order for production?
(a) 1, 4, 2 and 3
(b) 3, 4, 2 and 1
(c) 1, 4, 3 and 2
(d) 3, 2, 4 and 1

Answer: (a)

16. 
(a) Oil gas
(b) Coal gas
(c) Producer gas
(d) Water gas

Answer: (d)

17. Consider the following statements with reference to the water gas:
1. In order to enhance calorific value of water gas, it is carburetted by adding gaseous hydrocarbons
2. Its calorific value is about 6,500 Kcal per meter cube
3. It is employed for heating and illumination purpose
4. It contains about 55% of hydrogen

Which of the above statements are correct?
(a) 1 and 4 only
(b) 2 and 4 only
(c) 1 and 3 only
(d) 2 and 3 only

Answer: (c)

18. What is the significance of ‘Saponification Number ’?
(a) To determine the materials that may cause abrasion and wear
(b) To ascertain whether the oil under reference is animal and vegetable oil or mineral oil or a compounded oil containing mineral and vegetable oils
(c) To determine free acid present in the oil
(d) To judge the suitability of a lubricant under conditions of very high pressure

Answer: (b)

19. When oil is cooled slowly, the temperature at which it becomes hazy in appearance is called its:
(a) Flash point
(b) Fire point
(c) Pour point
(d) Cloud point

Answer: (d)

20. The percentage of asphalt present in oil is known as:
(a) Neutralization number
(b) Saponification number
(c) Emulsification number
(d) Precipitation number

Answer: (d)