MCQOPTIONS
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MCQOPTIONS
This section includes 463 Mcqs, each offering curated multiple-choice questions to sharpen your Mechanical Engineering knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
Water is used as a in air conditioning units. |
| A. | absorbent |
| B. | refrigerant |
| C. | absorbent and refrigerant |
| D. | none of the mentioned |
| Answer» C. absorbent and refrigerant | |
| 2. |
The vapour going to condenser is in temperature and in ammonia. |
| A. | higher, less |
| B. | higher, richer |
| C. | lower, less |
| D. | lower, richer |
| Answer» E. | |
| 3. |
A condenser must and then the compressed refrigerant. |
| A. | superheat, evaporate |
| B. | desuperheat, evaporate |
| C. | superheat, condense |
| D. | desuperheat, condense |
| Answer» E. | |
| 4. |
Superheating of vapour and subcooling of liquid the refrigerating effect. |
| A. | decreases |
| B. | increases |
| C. | no change |
| D. | none of the mentioned |
| Answer» C. no change | |
| 5. |
Compounding efficiency at low speed. |
| A. | decrease |
| B. | increase |
| C. | maximizes |
| D. | none of the mentioned |
| Answer» C. maximizes | |
| 6. |
Gas flows through the nozzle from an area of pressure (called the chamber) to one of pressure |
| A. | high, low |
| B. | low, high |
| C. | same, same |
| D. | constant, infinite |
| Answer» B. low, high | |
| 7. |
When a gas is pushed through a pipe, the gaseous molecules are by the pipe’s walls |
| A. | attracted |
| B. | absorbed |
| C. | deflected |
| D. | dissipated |
| Answer» D. dissipated | |
| 8. |
A cubical block rests on an inclined plane of μ = 1/√3, determine the angle of inclination when the block just slides down the inclined plane? |
| A. | 40° |
| B. | 50° |
| C. | 30° |
| D. | 20° |
| Answer» D. 20° | |
| 9. |
Critical pressure ratio is ratios of pressures at discharge. |
| A. | minimum |
| B. | none of the mentioned |
| C. | optimum |
| D. | maximum |
| Answer» E. | |
| 10. |
A mass of 4kg rests on a horizontal plane. The plane is gradually inclined until at an angle θ= 15° with the horizontal, the mass just begins to slide. What is the coefficient of static friction between the block and the surface? |
| A. | 0.814 |
| B. | 0.27 |
| C. | 1.5 |
| D. | 3.5 |
| Answer» C. 1.5 | |
| 11. |
When a gas is pushed through a pipe, the gaseous molecules are by the pipe’s walls |
| A. | attracted |
| B. | absorbed |
| C. | deflected |
| D. | dissipated |
| Answer» D. dissipated | |
| 12. |
The Parsons’ reaction turbine has ____________ |
| A. | only moving blades |
| B. | only fixed blades |
| C. | fixed and moving blades of different shape |
| D. | identical fixed and moving blades |
| Answer» E. | |
| 13. |
The Parsons’ reaction turbine has |
| A. | only moving blades |
| B. | only fixed blades |
| C. | fixed and moving blades of different shape |
| D. | identical fixed and moving blades |
| Answer» E. | |
| 14. |
If the speed of sound is much than that of the gas, the gas density will stay constant. |
| A. | smaller |
| B. | larger |
| C. | equal to |
| D. | non-existent |
| Answer» C. equal to | |
| 15. |
In what form are the boiler’s tube arrange in Lamont boiler? |
| A. | parallel in vertical |
| B. | inclined vertically |
| C. | parallel in horizontal |
| D. | horizontally inclined |
| Answer» D. horizontally inclined | |
| 16. |
In fountains the type of nozzle used is |
| A. | none of the mentioned |
| B. | turbulent jet |
| C. | high speed nozzle |
| D. | laminar jet |
| Answer» E. | |
| 17. |
Nozzle efficiency is defined as |
| A. | ratio of isentropic heat drop to useful heat drop |
| B. | ratio of useful heat drop to isentropic heat drop |
| C. | product of useful heat drop and isentropic heat drop |
| D. | none of the above |
| Answer» C. product of useful heat drop and isentropic heat drop | |
| 18. |
The capacity of a compressor is 5 m /min. 5 m /min refers to |
| A. | standard air |
| B. | free air |
| C. | compressed air |
| D. | compressed air at delivery pressure |
| Answer» C. compressed air | |
| 19. |
A nozzle is designed for |
| A. | maximum pressure at the outlet |
| B. | maximum discharge |
| C. | maximum pressure and maximum discharge |
| D. | maximum kinetic energy at the outlet |
| Answer» E. | |
| 20. |
In a pressure-compounded impulse steam turbine, pressure drop over each ring of moving blades |
| A. | remains constant |
| B. | is increasing |
| C. | is decreasing |
| D. | none of the above |
| Answer» B. is increasing | |
| 21. |
A pure substance exists in |
| A. | solid phase |
| B. | liquid phase |
| C. | gaseous phase |
| D. | all of the above |
| Answer» E. | |
| 22. |
Presence of frictional effect during flow through the nozzle |
| A. | reduces the exit velocity |
| B. | increases the exit velocity |
| C. | has no effect on exit velocity |
| D. | none of the above |
| Answer» B. increases the exit velocity | |
| 23. |
From inlet to exit of moving blades in case of a reaction turbine, the pressure |
| A. | increases |
| B. | decreases |
| C. | remains constant |
| D. | none of the above |
| Answer» C. remains constant | |
| 24. |
Which is false statement about multistage compression. |
| A. | Power consumption per unit of air delivered is low |
| B. | Volumetric efficiency is high |
| C. | It is best suited for compression ratios around 7:1 |
| D. | The moisture in air is condensed in the intercooler |
| Answer» C. It is best suited for compression ratios around 7:1 | |
| 25. |
During condensation process, the temperature of the condensing fluid |
| A. | remains constant |
| B. | decreases |
| C. | increases |
| D. | none of the above |
| Answer» B. decreases | |
| 26. |
The condensation of steam in a condenser takes place at |
| A. | constant pressure |
| B. | constant temperature |
| C. | constant pressure and constant temperature |
| D. | none of the above |
| Answer» D. none of the above | |
| 27. |
The work done per unit mass of air in compression will be least when n is equal to |
| A. | 1 |
| B. | 1.2 |
| C. | 1.3 |
| D. | 1.4 |
| Answer» B. 1.2 | |
| 28. |
In a recuperative air preheater, the heat is transferred |
| A. | from a metal wall from one medium to another |
| B. | from heating an itermediate material and then heating the air from this material |
| C. | by direct mixing , |
| D. | heat is tr |
| Answer» E. | |
| 29. |
Equivalent evaporation of water is the evaporation "for a feed water supply at 100°C |
| A. | and its corresponding conversion into dry saturated steam at 100°C and 1.033 kg/cm2 |
| B. | and its corresponding conversion into dry steam at desired boiler pressure |
| C. | conversion into steam at atmospheric condition |
| D. | conversion into steam at the same pres-sure at which feed water is supplied |
| Answer» B. and its corresponding conversion into dry steam at desired boiler pressure | |
| 30. |
What is a pure substance? |
| A. | homogeneous mixture of two substances of same composition |
| B. | a substance with constant chemical composition throughout its mass |
| C. | both a. and b. |
| D. | none of the above |
| Answer» C. both a. and b. | |
| 31. |
When heat is transferred from one particle of hot body to another by actual motion of the heated particles, it is referred toas heat transfer by |
| A. | conduction |
| B. | convection |
| C. | radiation |
| D. | conduction and convection |
| Answer» B. convection | |
| 32. |
In a velocity-compounded impulse steam turbine, steam expands in |
| A. | one set of nozzles only |
| B. | more than one set of nozzles |
| C. | fixed and moving blades |
| D. | none of the above |
| Answer» B. more than one set of nozzles | |
| 33. |
A condenser in a steam power plant is ....... |
| A. | Increases expansion ratio of steam |
| B. | Reduces back pressure of steam |
| C. | Reduces temperature of exhaust steam |
| D. | All of the above |
| Answer» E. | |
| 34. |
A condenser condenses the steam coming out from___________. |
| A. | Boiler |
| B. | Turbine |
| C. | Economiser |
| D. | Super heater |
| Answer» C. Economiser | |
| 35. |
What is the correct formula for net work done of reciprocating engine? |
| A. | Wnet = mean effective pressure × clearance volume |
| B. | Wnet = mean effective pressure × total volume of cylinder |
| C. | Wnet = mean effective pressure × displacement volume |
| D. | none of the above |
| Answer» D. none of the above | |
| 36. |
A simple impulse turbine consists of |
| A. | one set of nozzles and one set of moving blades |
| B. | two sets of nozzle and one set of moving blades |
| C. | one set each of fixed and moving blades |
| D. | none of the above |
| Answer» B. two sets of nozzle and one set of moving blades | |
| 37. |
A wet vapour can be completely specified by |
| A. | pressure only |
| B. | temperature only |
| C. | dryness fraction only |
| D. | pressure and dryness fraction. |
| Answer» E. | |
| 38. |
The vaccum obtainable in a condenser is dependent upon...... |
| A. | Capacity of ejector |
| B. | Quantity of steam to be handeled |
| C. | Types of condenser used |
| D. | Temperature of cooling water |
| Answer» E. | |
| 39. |
40% of incident radiant energy on the surface of a thermally transparent body is reflected back. If the transmissivity ofthe body be 0.15, then the absorptivity of surface is |
| A. | 0.45 |
| B. | 0.55 |
| C. | 0.40 |
| D. | 0.75 |
| Answer» B. 0.55 | |
| 40. |
The dry saturated steam at very low pressure, (5-10 kg/cm2) when throttled to atmosphere will become |
| A. | wet |
| B. | superheated |
| C. | remain dry satruated |
| D. | dry |
| Answer» C. remain dry satruated | |
| 41. |
From inlet to exit of steam nozzle, the pressure |
| A. | increases |
| B. | decreases |
| C. | remains constant |
| D. | none of the above |
| Answer» C. remains constant | |
| 42. |
The presence of friction in the nozzle |
| A. | increases the final dryness fraction of steam |
| B. | decreases the final dryness fraction of steam |
| C. | it does not affect the dryness fraction of steam |
| D. | none of the above |
| Answer» B. decreases the final dryness fraction of steam | |
| 43. |
In an experiment to determine dryness fraction of steam, the mass of water separated was 1.2 kg in 15 minutes and the mass of steam passed out in same time was 4.8 kg. Dryness fraction is |
| A. | 40% |
| B. | 25% |
| C. | 50% |
| D. | 80% |
| Answer» E. | |
| 44. |
When the back pressure of a nozzle is below the critical pressure, the nozzle is said to be |
| A. | under expanding flow |
| B. | over expanding flow |
| C. | choked flow |
| D. | none of the above |
| Answer» D. none of the above | |
| 45. |
In a pressure-compounded impulse steam turbine, steam expands in |
| A. | nozzles and fixed blades only |
| B. | moving blades only |
| C. | fixed and moving blades both |
| D. | none of the above |
| Answer» B. moving blades only | |
| 46. |
The surface condensers are preferred in steam power plant, because |
| A. | they require less coolant |
| B. | condensate can be reused |
| C. | they are more efficient |
| D. | none of the above |
| Answer» C. they are more efficient | |
| 47. |
The vacuum maintained in a condenser depends on |
| A. | pressure of cooling water |
| B. | temperature of cooling water |
| C. | back pressure maintained in the condenser |
| D. | all of the above |
| Answer» C. back pressure maintained in the condenser | |
| 48. |
It is required to produce large amount of steam at low pressure. Which boiler should be used ? |
| A. | pulverised fuel fired boiler |
| B. | cochran boiler |
| C. | lancashire boiler |
| D. | babcock and wilcox boiler |
| Answer» D. babcock and wilcox boiler | |
| 49. |
Lancashire 'boiler is a |
| A. | stationary fire tube boiler |
| B. | stationary water tube boiler |
| C. | water tube boiler with natural/forced circulation |
| D. | mobile fire tube boiler |
| Answer» B. stationary water tube boiler | |
| 50. |
When heat is transferred from hot body to cold body, in a straight line, without affecting the intervening medium, it isreferred as heat transfer by |
| A. | conduction |
| B. | convection |
| C. | radiation |
| D. | conduction and convection |
| Answer» D. conduction and convection | |