Solved Question Paper & Answer Key of Vocational Instructor in Maintenance & Operation of Marine Engines 490/15 - Kerala PSC

Date of exam: 03.03.2017

Exam Code 032/2017

Question Booklet Alpha Code A

1. In a diesel engine, fuel is ignited by:

a) Injecting Fuel

b) Spark plug

c) Heat resulting from compressing air that is supplied for combustion

d) Igniter

Ans: C - Heat resulting from compressing air that is supplied for combustion.

Explanation: In diesel engine, fuel is sprayed by the fuel injector at the end of compression stroke and heat resulting from the compressed air is supplied for combustion. In petrol engine. In petrol engine, fuel is ignited with the help of spark plug.

2. If the intake air temperature of  IC engine increases, its efficiency will :

a) decreases

b) increases

c) remain same

d) unpredictable

Ans: A - decreases

Explanation: When temperature increases, the ratio Cp/Cv (ie γ) decreases, so efficiency of IC engine decreases according to the efficiency expression of IC engine (say Otto Cycle). More over, practically, higher the intake temperature, then higher will  be the pressure during compression stroke (as PV=mRT and V is constant, P∝T), but pressure during power stroke is not so. So this will create mechanical friction and will decrease the efficiency.

3. Air fuel ratio of petrol engine is controlled by:

a) Governor

b) Injector

c) Fuel Pump

d) Carburettor

Ans: Carburettor

Explanation: Carburettor mixes air and fuel in case of SI engine

4. Which of the following is the lightest and most volatile liquid fuel

a) gasoline

b) fuel oil

c) diesel

d) kerosene

Ans: gasoline

Explanation: Gasoline is the lightest and most volatile fuel among the option. Diesel is least volatile fuel. However auto ignition temperature of diesel < auto ignition temperature of Kerosene < auto ignition temperature of petrol. This is the reason why diesel is used in CI engines and so only we use spark plug for igniting petrol engine

5. Ignition timing of multi cylinder engine can be adjusted by

a) rotating the crank

b) rotating the distributor

c) adjusting the spark plug gap

d) adjusting ignition coil position

Ans: B - rotating the distributor 

6. Breeder reactor has a conversion ratio of

a) zero

b) more than unity

c) less than unity

d) infinity

Ans: B, more than  unity

Explanation: Breeder reactor is a nuclear reactor with high neutron economy. It can generate more fissile materials than it consumes. So its conversion ratio is more than 1. Conversion ratio is defined as the ratio of average number of new fissile atoms created per fission. Conversion ratio is a measure of performance of the nuclear reactor.

7. In nuclear fission, each neutron that causes fission releases

a) no new neutron

b) at least one new neutron

c) many fold neutrons

d) more than one neutron

Ans: D - more than one neutron

8. Super heated steam is generated in the following reactor

a) boiling water

b) pressurized water

c) gas cooled

d) none of the above

Ans: A - boiling water

Explanation: Super heated steam will be generated in boiling water reactor (BWR)

9. First nuclear power plant in India is located at

a) Kota

b) Kerala

c) Tarapur

d) Kalpakkam

Ans: C- Tarapur (Maharashtra)

10. In boiling water reactor, moderator is 

a) coolant itself

b) graphite rod

c) ferrite rod

d) blanket of thorium

Ans: A - coolant itself

Explanation: In a boiling water reactor (BWR), both coolant and moderator are the same. De-mineralised water is used for both the purpose.

11. Basic tool in work study is

a) Graph paper

b) Process chart

c) Planning chart

d) Stop watch

Ans: D - Stop watch

Explanation: Stop watch is used in time study. Time study is a part of work study

12. Job evaluation is the method of determining the

a) relative worth of job

b) skills required by a worker

c) contribution of a worker

d) contribution of a job

Ans: A - relative worth of a job

13. Father of time study was

a) F W Taylor

b) H L Gantt

c) F B Gilberth

d) R M Barnes

Ans: F W Taylor

14. CPM is the

a) time oriented technique

b) event oriented technique

c) activity oriented technique

d) target oriented technique

Ans: C - activity oriented technique

Note: PERT - event oriented technique

15. Unit of energy in SI unit is

a) Watt

b) Joule

c) Joule/s

d) Joule/m

Ans: B - Joule

Note: SI unit of power is Watt

16. Super heated vapour behaves

a) exactly as gas

b) as steam

c) as ordinary vapour

d) approximately as gas

Ans: D - approximately as gas

17. Heat and Work are

a) Point functions

b) System properties

c) Path Function

d) Intensive property

Ans: C - Path Function

Explanation: Amount of Heat and work depends on the path of the process. Both heat and work are inexact differentials. However, properties are point functions. 

18. For reversible adiabatic process, change in entropy is

a) maximum

b) minimum

c) zero

d) negative

Ans: C - zero

Explanation: Reversible adiabatic process is an isentropic process. So change in entropy is constant.

Answer keys of the rest of the questions are given below. For further doubts in any questions, feel free to post in the comment section.

19. D  20. B  21. B  22. B  23. C  24. A  25. B  26. A  27. B  28. B  29. D  30. C  31. C  32.D  33.B  34. A 35. A 36. D  37. C  38. C  39. B  40. D  41. C  42. B 43. 44. D  45. A  46. B  47. B  48. C 49. D 50. A 51. C 52. B  53. B  54. A  55. C  56. A  57.B  58. A  59. A  60. C  61. B  62. D  63. C  64. B   65. D 66. A  67. A  68. A  69. B  70. A  71. D  72. 73. B  74. B  75. A  76. C  77. B  78. B 79. D  80.C  81. B 82. A  83. D  84. C  85. A  86. D  87. 88. D  89. C  90. D  91. A  92. B 93. A 94. D 95. B 96. D  97. C 98. A  99. C 100. B

Other useful link - 
1. Tips to prepare for Kerala PSC Assistant Engineer Mechanical Exam
2. Tips to prepare for Kerala PSC Assistant Director Exam - Industries & Commerce

3. Study materials useful for engineers in Kerala PSC exams. 
4. Previous year question papers for practice.

Disclaimer - The explanation given here is purely based on personal expertise. The final may or may not vary according to the PSC answer key.