McqMate
These multiple-choice questions (MCQs) are designed to enhance your knowledge and understanding in the following areas: Mechanical Engineering .
| 301. |
Engines are supercharged |
| A. | To increase engine durability |
| B. | To increase specific power output |
| C. | To increase air-fuel ratio |
| D. | To improve heat transfer |
| E. | To reduce combustion temperature |
| Answer» B. To increase specific power output | |
| 302. |
Thermodynamic equilibrium is completely defined by the specifications of the |
| A. | Internal energy |
| B. | Enthalpy |
| C. | Generalized displacements |
| D. | All above together |
| E. | None of the above |
| Answer» D. All above together | |
| 303. |
Within the boiler the temperature of steam is highest in |
| A. | Water drum |
| B. | water tubes |
| C. | Superheater outlet |
| D. | Water walls |
| E. | Superheater inlet |
| Answer» C. Superheater outlet | |
| 304. |
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 |
| A. | 1.2 ata |
| B. | 1.127 ata |
| C. | 2.327 ata |
| D. | 0.563 ata |
| E. | 0.073 ata |
| Answer» B. 1.127 ata | |
| 305. |
Which one of the following acts as ignition accelerator for C.I. engines fuel |
| A. | Acetone peroxide |
| B. | Hydrogen peroxide |
| C. | None of above |
| D. | n heptane |
| E. | Armatic compounds |
| Answer» A. Acetone peroxide | |
| 306. |
Paraffins in petrol have the general formula |
| A. | Cn Hn |
| B. | Cn H2n + 2 |
| C. | Cn H2n - 4 |
| D. | Cn H2n |
| E. | Cn H2n - 2 |
| Answer» B. Cn H2n + 2 | |
| 307. |
If an air cooled compressor gets over-heated during operation, the probable cause cannot be |
| A. | Direction of rotation wrong |
| B. | Valve strips broken |
| C. | Leadage in intercooler |
| D. | Insufficient lubricating oil |
| E. | Intake fliter clogged |
| Answer» C. Leadage in intercooler | |
| 308. |
The phenomenon of hunting is associated with |
| A. | Governors |
| B. | Gears |
| C. | Cloth mechanism |
| D. | Carburetors |
| E. | Tappet valves |
| Answer» A. Governors | |
| 309. |
The term regeneration is closely associated with |
| A. | Steam engines |
| B. | Steam turbines |
| C. | Diesel engines |
| D. | Gas engines |
| E. | Wankel engines |
| Answer» B. Steam turbines | |
| 310. |
The air standard efficiency of a turbine cycle is 56.5%, which one of the following may be Carnot efficiency between the temperature limits of the cycle? |
| A. | 75% |
| B. | 64% |
| C. | 50% |
| D. | 100% |
| E. | 56.50% |
| Answer» B. 64% | |
| 311. |
A wankel engine is |
| A. | Rotory engine |
| B. | Turbine engine |
| C. | Jet engine |
| D. | Reciprocating engine |
| E. | Hybrid engine |
| Answer» A. Rotory engine | |
| 312. |
The temperatures and pressures for boiler are given below. Which of these boilers can be classified as super-critical pressure boiler? |
| A. | 250 psi, 150?C |
| B. | 100 kg/cm2, 450?C |
| C. | 10 kg/cm2, 150?C |
| D. | 150 kg/cm2, 500?C |
| E. | 218 kg/cm2, 540?C |
| Answer» E. 218 kg/cm2, 540?C | |
| 313. |
Motor cycle not using deflector type piston usually utilise |
| A. | Reverse flow scavanging |
| B. | Ideal scavanging |
| C. | Uniflow scavanging |
| D. | Natural scavanging |
| E. | Loop scavanging |
| Answer» A. Reverse flow scavanging | |
| 314. |
Direction of feed water is done because |
| A. | It reduces weight of water to be handled |
| B. | It reduced priming difficulties in feed pumps |
| C. | It reduces corrosion caused by oxygen present in air |
| D. | It reduces amount of heat required to convert water into steam |
| E. | None of the above |
| Answer» C. It reduces corrosion caused by oxygen present in air | |
| 315. |
The dryness fraction of steam within a turbine is usually not allowed to fali below |
| A. | Unity |
| B. | 0.45 |
| C. | 0.8 |
| D. | 0.9 |
| E. | 0.99 |
| Answer» D. 0.9 | |
| 316. |
Which of the following is an accessory for a boiler? |
| A. | Stop valve |
| B. | Feed check valve |
| C. | Safety valve |
| D. | Feed pump |
| E. | Blow off c*ck |
| Answer» D. Feed pump | |
| 317. |
The molecules move in a solid |
| A. | At random |
| B. | Back and forth like tiny pendulum |
| C. | In irregular motion |
| D. | In circular motion |
| E. | None of above |
| Answer» B. Back and forth like tiny pendulum | |
| 318. |
In all a four stroke four cylinder engine will have how many valves? |
| A. | 8 |
| B. | 16 |
| C. | none |
| D. | 4 |
| E. | Carbon dioxide |
| Answer» A. 8 | |
| 319. |
Latent heat is |
| A. | Heat required to change the state or condition under which the substance exists |
| B. | Heat that does not follow first law of thermodynamics |
| C. | Heat required to change the state of substance from liquid state to solid state |
| D. | Heat required to change the substance from solid to gaseous state |
| E. | Heat cannot be detected |
| Answer» A. Heat required to change the state or condition under which the substance exists | |
| 320. |
Steam consumption per kWh of electricity generated in a modern power plant is of the order of |
| A. | 10 -12 kgs |
| B. | 5 - 7 kgs |
| C. | 8 - 10 kgs |
| D. | 2 - 4 kgs |
| E. | 1 - 2 kgs |
| Answer» B. 5 - 7 kgs | |
| 321. |
In jet engines the compression ratio |
| A. | Varies with square of speed |
| B. | Remains constant |
| C. | Varies with altitude |
| D. | Depends on other factors |
| E. | Varies with altitude |
| Answer» A. Varies with square of speed | |
| 322. |
An Orsat's apparatus is used for |
| A. | None of above |
| B. | Gravimetric analysis of the flue gases |
| C. | Volumetric analysis of the flue gas |
| D. | Smoke density analysis of the flue gases |
| E. | All of above |
| Answer» C. Volumetric analysis of the flue gas | |
| 323. |
Motoring test on I.C. engines is conducted to measure |
| A. | I.H.P. |
| B. | B.H.P. |
| C. | Pumping horse power |
| D. | Friction horse power |
| E. | None of the above |
| Answer» D. Friction horse power | |
| 324. |
The turbidity in boiler feed water causes |
| A. | Sludge |
| B. | Scale |
| C. | Corrosion |
| D. | Embrittlement |
| E. | None of the above |
| Answer» A. Sludge | |
| 325. |
Steam leaves the steam nozzle at |
| A. | Low pressure and low velocity |
| B. | Low pressure and high velocity |
| C. | High pressure and low velocity |
| D. | High pressure and high velocity |
| E. | None of the above |
| Answer» B. Low pressure and high velocity | |
| 326. |
In diesel engines thermal efficiency may be expected in the range |
| A. | 35 to 40 percent |
| B. | 10 - 15 percent |
| C. | 15 to 25 percent |
| D. | 50 percent |
| E. | 25 to 30 percent |
| Answer» A. 35 to 40 percent | |
| 327. |
In reciprocating air compressor, the method of controlling the quantity of air delivered is done by |
| A. | Clearance Control |
| B. | Throttle Control |
| C. | Blow-off Control |
| D. | All of the above |
| E. | Carbon dioxide |
| Answer» D. All of the above | |
| 328. |
Motor cycles generally have |
| A. | Evaporative cooling system |
| B. | Natural cooling engines |
| C. | Ice cooled engines |
| D. | Natural cooling engines |
| E. | Air cooled engines |
| Answer» E. Air cooled engines | |
| 329. |
Crankcase dilution is |
| A. | Dilution of fuel in crank case |
| B. | Dilution of lubricating oil in crankcase |
| C. | Dilution of mixture while passing through crankcase in two stroke engines |
| D. | Addition of water in crankcase |
| E. | None of the above |
| Answer» B. Dilution of lubricating oil in crankcase | |
| 330. |
In an analysis report of a sample of coal the percentage of one of the constituents is specified as 3.5%. This constituent could be |
| A. | Carbon |
| B. | Ash |
| C. | Moisture |
| D. | Sulphur |
| E. | Any of the above |
| Answer» D. Sulphur | |
| 331. |
A plant costing Rs. 80,000 has a useful life of 12 years. The amount that should be saved annually to replace the equipment at the end of useful life with salvage value of Rs. 8,000 should be |
| A. | Rs. 15000 |
| B. | Rs. 8000 |
| C. | Rs. 6000 |
| D. | Rs. 5000 |
| E. | Rs. 10000 |
| Answer» C. Rs. 6000 | |
| 332. |
In a spark ignition engine supercharging |
| A. | Decreases knocking tendency |
| B. | There is no effect on knocking |
| C. | Increases knocking tendency |
| D. | Knocking is affected by other factors |
| E. | 1000 hours |
| Answer» C. Increases knocking tendency | |
| 333. |
A passout turbine generally operates on low pressure in the range |
| A. | 10 - 20 kg/cm2 |
| B. | 100 - 150 kg/cm2 |
| C. | 20 - 50 kg/cm2 |
| D. | 150 - 300 kg/cm2 |
| E. | 50 - 100 kg/cm2 |
| Answer» A. 10 - 20 kg/cm2 | |
| 334. |
In a reaction turbine while steam flows through the fixed blades |
| A. | Velocity increases |
| B. | Velocity decreases |
| C. | Velocity increases while pressure drops |
| D. | Pressure increases |
| E. | Neither admission pressure nor cut off is varied |
| Answer» C. Velocity increases while pressure drops | |
| 335. |
For steam engine having a throttle governor, a straight line is obtained when the total weight of steam used per hour is plotted against the indicated horse power. This line is known as |
| A. | Willian's line |
| B. | Clapeyron's line |
| C. | Bunsen line |
| D. | Calender's line |
| E. | Hopson's line |
| Answer» A. Willian's line | |
| 336. |
Ignition accelerators are used primarily to |
| A. | Reduce exhaust temperature |
| B. | Convert carbon monoxide into carbon dioxide |
| C. | Reduce combustion knock |
| D. | Cool the engine cylinder |
| E. | All of the above |
| Answer» C. Reduce combustion knock | |
| 337. |
A gas turbine power plant suits as |
| A. | Peak load plant |
| B. | Casual run plant |
| C. | Base load plant |
| D. | All of the above |
| E. | None of the above |
| Answer» A. Peak load plant | |
| 338. |
In diesel engines, the accumulation of carbon in the cylinder increases |
| A. | Mechanical efficiency |
| B. | Volumetric efficiency |
| C. | Ignition delay period |
| D. | Effective compression ratio |
| E. | Clearance volume |
| Answer» D. Effective compression ratio | |
| 339. |
Which of the following is the internal loss of a turbine? |
| A. | None of above |
| B. | Blade friction loss |
| C. | Nozzle loss |
| D. | All of above |
| E. | Wheel friction loss |
| Answer» B. Blade friction loss | |
| 340. |
Which of the following is not a property of carbondioxide? |
| A. | Non-toxic |
| B. | Non-inflammable |
| C. | Colourless |
| D. | Pungent odour |
| E. | None of the above |
| Answer» D. Pungent odour | |
| 341. |
A heat exchanger that can remove fixed quantity of heat from a system is available where should it be installed for best economy |
| A. | Anywhere |
| B. | As intercooler |
| C. | After final stage compression |
| D. | Depends upon size of installation |
| E. | Prior to first stage compression |
| Answer» E. Prior to first stage compression | |
| 342. |
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 |
| A. | Eight times |
| B. | No change |
| C. | Sixteen times |
| D. | Doubled |
| E. | Four times |
| Answer» E. Four times | |
| 343. |
A 50 cfm compressor can |
| A. | Compress 50 cu feet per min of free air |
| B. | Compress 50 cu feet per min of standard air |
| C. | Deliver 50 cu feet of compressed air at delivery pressure |
| D. | Delivers 50 cu ft. per minute of compressed air |
| E. | None of the above |
| Answer» A. Compress 50 cu feet per min of free air | |
| 344. |
A perfect heat engine works on the Carnot cycle between 1000?C and 200?C. The efficiency of the engine will be |
| A. | 42.80% |
| B. | 60% |
| C. | 62.80% |
| D. | 80% |
| E. | 37.20% |
| Answer» C. 62.80% | |
| 345. |
A gas turbine works on |
| A. | Dual cycle |
| B. | Brayton cycle |
| C. | Carnot cycle |
| D. | Otto cycle |
| E. | Rankine cycle |
| Answer» B. Brayton cycle | |
| 346. |
In power station practice 'spinning reserve' is |
| A. | Reserve generating capacity that is in operation but in service |
| B. | Reserve generating capacity that is connected to bus and ready to take load |
| C. | Reserve generating capacity that is available for service but not in operation |
| D. | Capacity of the part of plant that remains under maintenance |
| E. | None of the above |
| Answer» B. Reserve generating capacity that is connected to bus and ready to take load | |
| 347. |
Ash content of a diesel fuel oil should not exceed |
| A. | 0.50% |
| B. | 0.05% |
| C. | 1% |
| D. | 0.01% |
| E. | 0.10% |
| Answer» D. 0.01% | |
| 348. |
Injector is used to |
| A. | Inject wet steam into superheater |
| B. | Inject steam into steam engine cylinder |
| C. | Inject secondary air in boiler furnace |
| D. | Inject water boiler |
| E. | Inject exhaust gases into chimney |
| Answer» D. Inject water boiler | |
| 349. |
A barn is a |
| A. | Unit of momentum |
| B. | Unit of time |
| C. | Unit of area |
| D. | Unit of length |
| E. | Unit of mass |
| Answer» C. Unit of area | |
| 350. |
High steam and low water safety valve is not used on which of the following boiler? |
| A. | Locomotive boiler |
| B. | Cornish boiler |
| C. | Cochran boiler |
| D. | Lancashire boiler |
| E. | All of the above |
| Answer» A. Locomotive boiler | |
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