1. Octane number of petrol generally available is in the range 25 to 60 10 to 25 80 to 100 55 to 65 2. High steam and low water safety valve is not used on which of the following boiler? Cornish boiler Lancashire boiler Locomotive boiler Cochran boiler 3. In spark ignition engines, the knocking tendency is reduced by Reduction of compression ratio Increasing exhaust temperature Adding dope like tetra ethy lead to the fuel Advancing ignition timing 4. A perfect heat engine works on the Carnot cycle between 1000?C and 200?C. The efficiency of the engine will be 80% 42.80% 62.80% 60% 5. A heat exchanger that can remove fixed quantity of heat from a system is available where should it be installed for best economy As intercooler Anywhere After final stage compression Prior to first stage compression 6. The bottom ring on the piston is known as Compression ring Scrapper ring Oil ring Groove ring 7. Normally the colour of exhaust from a petrol engine is Black Reddish Yellowish Bluish 8. Scavenging efficiency of a four stroke diesel engine is Between 100% and 95% In the range 80 to 95 percent In the range 50 - 80 percent Below 50 percent 9. Which one of the following symptoms will not show that combustion is becessary complete. Presence of carbon monoxide in exhaust Presence of free carbon in exhaust Presence of oxygen in exhaust Presence of nitrogen in exhaust 10. In thermodynamic analysis, a pure substance is that which behaves as perfect gas May have a number of chemical species that the composition remains constant has no dissolved impurities consists of only a single chemical species 11. A closed vessel contains air at 1.2 ata and 57?C. The pressure of air in the vessel if the contents of the vessel are cooled to 37?C would be 0.563 ata 1.127 ata 1.2 ata 2.327 ata 12. Steam leaves the steam nozzle at High pressure and low velocity Low pressure and high velocity High pressure and high velocity Low pressure and low velocity 13. If a steam injector lifts the water but fails to force it into the boiler, the trouble may not be due to Combining tube clogged Leake in water pipe Insufficient steam pressure Sry steam 14. Engines are supercharged To increase engine durability To increase air-fuel ratio To increase specific power output To improve heat transfer 15. Within the boiler the temperature of steam is highest in water tubes Water walls Superheater outlet Water drum 16. Which one of the following acts as ignition accelerator for C.I. engines fuel Hydrogen peroxide n heptane Acetone peroxide None of the options 17. Presence of impurities in ice Lowers melting point Makes it heavier than water Raises melting point Does not have any effect 18. Generally steam turbines in power station operate at 375 RPM 1000 RPM 50 RPM 3000 RPM 19. Which statement is false in case of SI engines Adding methyl groups to the side of the carbon chain increases the knocking tendency Unsaturated aliphatic hydrocarbons show less knocking tendency Increasing the length of the carbon chain increases the knocking tendency Accetylene has least tendency to knocking 20. Thermodynamic equilibrium is completely defined by the specifications of the Internal energy Generalized displacements All above together Enthalpy 21. A 50 cfm compressor can Deliver 50 cu feet of compressed air at delivery pressure Delivers 50 cu ft. per minute of compressed air Compress 50 cu feet per min of standard air Compress 50 cu feet per min of free air 22. When steam expands without doing mechanical work, its enthalpy Does not change Depends on the factors Decreases Increases 23. Which of the following is false statement? The cause of slow cranking of a gas engine during starting may be Under capacity battery High air temperature Heavy engine oil Partially discharged battery 24. Which of the following is a false statement. A multicylinder diesel engine is missing on one or more cylinders. The cause may be Valve sticky Insufficient fuel supply to cylinders Air cleaner plugged Compression poor 25. The steam in a boiler drum is always Dry Wet Wet or dry and saturated Dry and saturated 26. The work done on a compressor will be least when air is taken from As and where available Source of low temperature air A source at 0?C Atmosphere 27. In a petrol engine as the speed increases The spark intensity has to be reduced The spark has to be retarded The spark has to be advanced The spark intensity has to be increased 28. Anthydrous substance is Free of hydrogen Dry substance Free of water specially water of crystallization Free of humidity 29. Thermionic converters are based on Microwave theory Seebeck effect Energy contained in thermal conductors Transfer of electrons 30. In thermodynamics, forced processes are those Where a difference is observed in any microscopic property of the system between different times or states Which require an agency outside the system to force the process Where a difference is observed in any microscopic property of the system between different times of states Which occur in the direction of an intensive property or driving force contained within the system 31. Motoring test on I.C. engines is conducted to measure Pumping horse power I.H.P. B.H.P. Friction horse power 32. Fuel which detonates easily is Alcohol Iso-octane Toulene n-Heptane 33. A fan is being operated in an environment for which information is available. Now if the fan speed is doubled, how will the static pressure vary Four times No change Eight times Sixteen times 34. Cetane number of diesel generally used in India is in the range 15 to 20 20 to 25 55 to 65 40 to 55 35. In jet engines the compression ratio. Remains constant Varies with square of speed Varies with altitude Depends on other factors 36. The boilers using lignite as fuel do not use Travelling grate stoker Horizontal burner, pulverized fuel U-flame pulverized fuel burner Underfeed stoker 37. The turbidity in boiler feed water causes Sludge Scale Corrosion Embrittlement 38. Leaking radiator tubes are generally Brazed Soldered Welded Left unattended 39. An Orsat's apparatus is used for Smoke density analysis of the flue gases Volumetric analysis of the flue gas Gravimetric analysis of the flue gases None of the options 40. In compression ignition engine fuel ignition accelerators are added to Reduce combustion chamber temp Accelerate combustion knock Reduce combustion knock Increase delay period 41. For the same power and same speed, the flywheel of a two stroke engine as compared to that of a four stroke engine will be Same size Bigger Small There is no correlation 42. Which of the following chemical acts as anti-freeze? Glycol Ethyl alcohol Lead acetate Naphtha 43. In a Carnot cycle the algebraic sum of the entropy changes for the cycle is Zero Either positive or negative Negative Depends on the properties of working substance 44. As the compression ratio increases the volumetric efficiency of air compressor Increases Does not change Decreases Unpredictable 45. Ambassador car engine is L-type Side valve type F-type Overhead valve type 46. In jet engines the compression ratio Varies as cube of speed Varies with altitude Varies with square of speed Remains constant 47. Steam trap is a device that Allows passage of air but prevents passage of steam Allows passage of the flue gases but prevents flow of steam Allows passage of water but prevents the passage of steam None of the options 48. Blue smoke from a diesel engine indicates the presence of Unburnt oil Carbon monoxide Carbon dioxide Unburnt carbon 49. Which is not the cause for loss of heat in boiler due to incomplete combustion? Under cooling of furnace at low ratings Improper secting of boiler Boiler drum uninsulated Insufficient air supply 50. A turbo-charger is used In rockets for producing air fuel mixture In jet propulsion units For supercharging reciprocating engine In gas turbines for compression of air Submit Answers Retake Test More Mechanical Engineering Study Material › Mechanical Engineering Mock Tests with AnswersApplied Mechanics Mock TestAutoCAD Mock TestAutomobile Engineering Mock TestCAD CAM and Automation Mock TestDesign of Machine Elements Mock TestDynamics of Machinery Mock TestDynamics of Machines Mock TestElectrical Drives and Controls Mock TestElectrical and Electronics Engineering Mock TestEnergy Conversion Mock TestEngineering Materials Mock TestEngineering Metallurgy Mock TestEngineering Thermodynamics Mock TestEnvironmental Engineering Mock TestFabrication Technology Mock TestFluid Mechanics and Hydraulic Machines Mock TestFluid Mechanics and Machinery Mock TestFoundry Technology Mock TestHeat Engines Mock TestHeat Transfer Mock TestIndustrial Engineering Mock TestInternal Combustion Engines Mock TestMachine Design Mock TestManufacturing Processes Mock TestManufacturing Technology Mock TestMass Transfe Mock TestMaterial Handling Mock TestMechanical Measurements Mock TestMechatronics Mock TestMetallurgy Mock TestMetrology and Measurements Mock TestNon Destructive Testing and Evaluation Mock TestPower Plant Engineering Mock TestPrinciples of Food Preservation Mock TestPrinciples of Programming Languages Mock TestProblem Solving and Python Programming Mock TestProcess Planning and Cost Estimation Mock TestProduct Design and Value Engineering Mock TestProduction Engineering Mock TestRefrigeration and Air conditioning Mock TestStrength of Materials Mock TestTheory of Machines Mock TestTheory of Mechanics Mock TestThermal Engineering Mock TestThermodynamics Mock TestTotal Quality Management Mock TestTurbo Machines Mock TestUnconventional Machine Process Mock TestUsability Engineering Mock Test Mechanical Engineering Mock Tests
