Electrical Engg. By Ashish sir

47.Why is pulverised coal used? a. Better burning. b. Increased calorific value of coal. c. Medium size units. d. Less radiation loss.

46. What is pulverised coal? a. Non smoking coal. b. Coal free from ash. c. Coal broken into fine particles. d. Coal which burns for long time.

45. Which of the following is/are an/ the essential element/s for the combustion of fuel? a. Oxygen b. Correct fuel air ratio. c. Proper ignition temperature. d. All of these.

44. What is the percentage of ash content in Indian coal? a. 5 % b. 10 % c. 20 % d. 30 %

43 The elements that are combustible in the fuel are a. Carbon and hydrogen. b. Carbon, hydrogen and ash. c. Carbon, hydrogen and sulphur. d. Carbon, nitrogen and ash.

42. On which factor does the calorific value of coal depend? a. Ash content. b. Size of coal particles c. Moisture content. d. Volatile material.

41. The major content of coal in India is ________________. a. Dust b. Ash c. Fly ash d. Cinder

40.The coal with highest ash content is ________. a. Lignite b. Steam coal c. Coking coal d. Bituminous coal

39. What is the superior quality of coal called? a. Anthracite b. Coke c. Bituminous d. Peat

38. Name the system that is mainly employed for the disposal of fly ash. a. Pneumatic b. Hydraulic c. Both (a) & (b) d. Steam jet system

37. The best coal suitable for the production of energy is_________________. a. Lignite b. Bituminous c. Anthracite d. Peat

36. Evaporative type of condenser has a. Water in pipes surrounded by steam outside. b. Steam and cooling water mixed to give the condensate. c. Steam in pipes surrounded by water. d. None of the above.

35. Spray ponds are used to cool the warm water coming from the condenser in ________. a. Large power plants b. Small power plants c. Medium power plants d. Both medium and large power plants.

34.What is use of the air pumps in the condenser? a. Remove water b. Air leaking in the condenser and to maintain the vacuum c. Maintain atmospheric pressure and the condenser d. Both (a) & (b)

33.Water used in the steam plant is used for cooling in_______________. a. Condenser b. Turbine only c. Boiler tube d. Boiler tubes and turbines

32. A condenser condenses the steam coming out from___________. a. Boiler b. Turbine c. Economiser d. Super heater

31. The draught produced by the chimney is________________. a. Forced draught b. Natural draught c. Induced draught d. Balanced draught

30.Air- preheater in a steam power plant_____________. a. Recovers the heat from the flue gases leaving the economiser. b. Improves combustion rate. c. Raises the temperature of the furnace gases. d. All of these.

29.The use of air preheater increase the temp of the air by about______________. a. 50° b. 20° c. 5° d. 30°

28. The reheat factor in a steam turbine depends on a. Stage efficiency. b. Initial pressure and temperature. c. Exit pressure. d. All of the above.