MCQOPTIONS
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MCQOPTIONS
This section includes 460 Mcqs, each offering curated multiple-choice questions to sharpen your Heat Engines knowledge and support exam preparation. Choose a topic below to get started.
| 251. |
Load curve is the plot of |
| A. | Load versus generatng capacity |
| B. | Load versus current |
| C. | Load versus time |
| D. | Load versus cost of power |
| E. | None of the above |
| Answer» D. Load versus cost of power | |
| 252. |
The processes in a Rankine cycle are |
| A. | Two isothermal and two isentropic |
| B. | Two isothermal and two polytropic |
| C. | Two isothermal and two isobaric |
| D. | One constant pressure, one constant volume and two polytropic |
| E. | None of the above |
| Answer» F. | |
| 253. |
Apart from reducing friction and cooling the surfaces, the function of lubricant in I.C. engines is |
| A. | To improve thermal efficiency |
| B. | To clean the surfaces by carrying away the carbon and metal particles cansed by wear |
| C. | To reduce noise |
| D. | To reduce vibrations |
| E. | None of the above |
| Answer» C. To reduce noise | |
| 254. |
Percentage improvement in power in case of a four stroke diesel engine with the help of a supercharger may be expected in the range |
| A. | 25 |
| B. | 35 |
| C. | 75 |
| D. | 50 |
| E. | 100 |
| Answer» D. 50 | |
| 255. |
With reference to a safety valve the blow down pressure is the pressure at which |
| A. | Valve opens |
| B. | Valve closes after opening |
| C. | Valve opens initially |
| D. | Valve spring pressure is adjusted |
| E. | None of the above |
| Answer» C. Valve opens initially | |
| 256. |
A Lenoir cycle has a top temperature in the cycle |
| A. | More than that of Otto cycle |
| B. | Equal to diesel cycle |
| C. | Weight of engine |
| D. | Between Otto and diesel cycles |
| E. | Less than diesel cycle |
| Answer» E. Less than diesel cycle | |
| 257. |
A Lungistrom turbine is |
| A. | Impulse turbine |
| B. | Reaction turbine |
| C. | Outward radial flow turbine |
| D. | Inward flow impulse reaction turbine |
| E. | None of the above |
| Answer» D. Inward flow impulse reaction turbine | |
| 258. |
A radiation pyrometer is used for temperatures |
| A. | Upto 100?C |
| B. | Below 100?C |
| C. | Above 500?C |
| D. | 250 - 500?C |
| E. | 100 - 250?C |
| Answer» D. 250 - 500?C | |
| 259. |
In a Diesel engine the duration between the time of injection and time of ignition is called |
| A. | Explosion period |
| B. | Delay period |
| C. | Period of ignition |
| D. | Pre-ignition period |
| E. | Burning period |
| Answer» C. Period of ignition | |
| 260. |
One kg of octane is burnt by four alternative processes given below. In which case the work available will be maximum? |
| A. | When burnt in an open pan in atmosphere |
| B. | When burnt in an internal combustion engine |
| C. | When burnt in a fuel cell |
| D. | When burnt in a reversible process |
| E. | None of the above |
| Answer» E. None of the above | |
| 261. |
The lowest temperatures that can be measured by a gas thermometer using nitrogen is |
| A. | ? 100?C |
| B. | 0?C |
| C. | ? 200?C |
| D. | ? 10?C |
| E. | ? 137?C |
| Answer» D. ? 10?C | |
| 262. |
A starting motor should have capacity to generate power equal to |
| A. | IHP |
| B. | IHP-BHP |
| C. | BHP |
| D. | Friction horse power at cranking r.p.m |
| E. | Friction horse power |
| Answer» E. Friction horse power | |
| 263. |
Tidal power is the power generated from |
| A. | Raw sea water |
| B. | Waves of the ocean |
| C. | Rise and fall tides |
| D. | Thermal energy of ocean water |
| E. | Chemicals in sea water |
| Answer» D. Thermal energy of ocean water | |
| 264. |
Rank of coal is based on |
| A. | Fixed carbon and heating value |
| B. | Ash content |
| C. | Ash and moisture content |
| D. | Size |
| E. | None of the above |
| Answer» B. Ash content | |
| 265. |
Gusset stays are provided in |
| A. | Steam turbines |
| B. | Steam condensers |
| C. | Chimney |
| D. | Boilers |
| E. | Steam engines |
| Answer» E. Steam engines | |
| 266. |
Dark, black smoke from diesel engines usually results when the engine is |
| A. | Idling |
| B. | Running at slow speeds |
| C. | Running at full speed but under no load conditions |
| D. | Running at full load and full speed |
| E. | Running at light loads |
| Answer» E. Running at light loads | |
| 267. |
Which of the following is an important consideration in the design of turbine blades? |
| A. | Creep |
| B. | Shape |
| C. | Exhaust temperature |
| D. | Air-fuel ratio |
| E. | None of the above |
| Answer» B. Shape | |
| 268. |
Resilience is the property of materials in which |
| A. | Materials resist deformation |
| B. | Materials spring back or recoil when pressure is removed |
| C. | Materials are easily deformed |
| D. | Materials can be easily pressed |
| E. | None of the above |
| Answer» C. Materials are easily deformed | |
| 269. |
Sensible heat is |
| A. | That heat which causes change of state |
| B. | That heat which produces a rise of temperature |
| C. | That heat which produces a rise of temperature |
| D. | That can only be sensed by a thermometer |
| E. | None of the above |
| Answer» D. That can only be sensed by a thermometer | |
| 270. |
In a throttle governed steam engine |
| A. | Admission pressure is reduced while cut off remains unaltered |
| B. | Admission pressure remains constant while cut off is altered |
| C. | Admission pressure and cut off both are altered |
| D. | Admission pressure is varied while cut off remains unaltered |
| E. | Neither admission pressure nor cut off is altered |
| Answer» E. Neither admission pressure nor cut off is altered | |
| 271. |
The self-ignition temperature of diesel oil as compared to petrol is |
| A. | Higher |
| B. | Varies considerably |
| C. | Lower |
| D. | Depends on other factors |
| E. | Same |
| Answer» B. Varies considerably | |
| 272. |
In isochronous governors the speed drop is |
| A. | 50 percent |
| B. | 75 percent |
| C. | 10 percent |
| D. | 20 percent |
| E. | Zero |
| Answer» F. | |
| 273. |
This purpose of supercharging an engine is |
| A. | To increase the power output of engine |
| B. | To reduce specific fuel consumption |
| C. | To reduce the noise of engine |
| D. | To improve cooling of cylinders |
| E. | None of the above |
| Answer» B. To reduce specific fuel consumption | |
| 274. |
The effieincy of a diesel cycle increases with |
| A. | increase in cut off |
| B. | decrease in cut off |
| C. | decrease in compression ratio |
| D. | None of the above |
| E. | Carbon dioxide |
| Answer» C. decrease in compression ratio | |
| 275. |
Intercooling in multistage compressors is done |
| A. | To supply-air at two different pressures for use |
| B. | To cool air during compression |
| C. | To cool the air at delivery |
| D. | To enable use of small cylinders and eliminate problems of unbalanced forces |
| E. | To minimise the work of compression |
| Answer» F. | |
| 276. |
All but one of the following possible steam generator test difficulties would cause the apparent performance to be poorer than it actually is. One item would make the performance look better than it really is. Identify the item |
| A. | Steam flow meter reads low |
| B. | Steam temperature gauge reads too high |
| C. | HHV of fuel is determined incorrectly, being too high |
| D. | Coad scales are inaccurate, reading high |
| E. | None of the above |
| Answer» E. None of the above | |
| 277. |
Thermie |
| A. | Is quantity of heat required to raise temperature of one tonne of water from 14.5?C to 15.5?C |
| B. | Is a unit of latent heat measurement |
| C. | Is thermal conductivity of materials |
| D. | Is a unit of temperature measurement |
| E. | Is the temperature change in water when 1000 calories of heat are added to 1 gm of water, gradually |
| Answer» B. Is a unit of latent heat measurement | |
| 278. |
For gas turbines compressors used are |
| A. | Centrifugal type |
| B. | Lobe type |
| C. | Axial flow type |
| D. | Sliding vane type |
| E. | Reciprocating type |
| Answer» D. Sliding vane type | |
| 279. |
Piston rings are made of |
| A. | Aluminium |
| B. | Carbon steel |
| C. | Alloy steel |
| D. | Copper |
| E. | Cast iron |
| Answer» F. | |
| 280. |
Induced draft fan for a boiler is always located |
| A. | Near the cooling tower |
| B. | At the foot of the chimney |
| C. | Near the coal hopper |
| D. | Near the water treatment |
| E. | On the top of the chimney |
| Answer» C. Near the coal hopper | |
| 281. |
Live storage of fuel means |
| A. | Fuel stored to meet day's requirement for the boiler |
| B. | Fuel stored for supply at any time during emergency |
| C. | Fuel stored at the plant |
| D. | Fuel stored near the burners |
| E. | None of the above |
| Answer» B. Fuel stored for supply at any time during emergency | |
| 282. |
For superheated steam in a nozzle the critical pressure ratio is |
| A. | 0.528 |
| B. | 0.546 |
| C. | 0.64 |
| D. | 0.577 |
| E. | 1 |
| Answer» C. 0.64 | |
| 283. |
In a four stroke petrol engine |
| A. | Intake valve closes before TDC |
| B. | Intake valve closes after BDC |
| C. | Exhaust valve closes before BDC |
| D. | Exhaust valve open before BDC |
| E. | None of the above |
| Answer» C. Exhaust valve closes before BDC | |
| 284. |
In regenerative feed heating system the steam 'bled' from turbine exchanges heat with |
| A. | High pressure steam coming from boiler |
| B. | Air for preheating |
| C. | Fuel for preheating |
| D. | Feed water for boiler |
| E. | All of the above |
| Answer» E. All of the above | |
| 285. |
Which of the following is a false stagement: The cause of excessive engine vibrations especially at high speeds in spark ignition engines is |
| A. | Unequal distribution of mixture |
| B. | Unbalanced crankshaft |
| C. | Unequal compression of engine cylinders |
| D. | Ignition distributor point not synchrohized |
| E. | Unbalanced fan or loose fan blade |
| Answer» B. Unbalanced crankshaft | |
| 286. |
Shock effect in the nozzle generally occurs in |
| A. | Inlet |
| B. | Converging section |
| C. | Throat |
| D. | Diverging section |
| E. | Exit |
| Answer» E. Exit | |
| 287. |
Which part of a gas turbine is subjected to the highest temperature? |
| A. | Blades |
| B. | Regenerator |
| C. | Intercooler |
| D. | Compressor coupling |
| E. | Compressed air |
| Answer» B. Regenerator | |
| 288. |
The missing quantity in a steam engine can be reduced by all of the following methods EXCEPT |
| A. | Superheating the steam supplied to the engine |
| B. | Steam jacketing of cylinder walls |
| C. | Reducing the speed of the engine |
| D. | Dompounding the expansion of steam in two or more cylinders |
| E. | 85% octane + 15% heptane |
| Answer» D. Dompounding the expansion of steam in two or more cylinders | |
| 289. |
Which one of the following is not a constituent of coal |
| A. | Carbon |
| B. | Manganese |
| C. | Inorganic matter |
| D. | Hydrogen |
| E. | Nitrogen |
| Answer» C. Inorganic matter | |
| 290. |
In the Bomb calorimeter the fuel to be tested is burned |
| A. | There is no consideration of pressure, volume or temperature. |
| B. | At constant temperature |
| C. | At constant volume |
| D. | In open atmosphere |
| E. | At constant pressure |
| Answer» D. In open atmosphere | |
| 291. |
The maximum horse power of a 150 CC scooter engine is around |
| A. | 3 |
| B. | 1.5 |
| C. | 15 |
| D. | 8 |
| E. | 33 |
| Answer» E. 33 | |
| 292. |
Boilers using Bagasse as fuel use |
| A. | Travelling grate stroker |
| B. | Underfeed stokers |
| C. | Pulverized fuel burners |
| D. | Chain grate stokers |
| E. | Spreader stokers |
| Answer» F. | |
| 293. |
In case of glass tube type water level indicator for a boiler |
| A. | One end of the tube is connected to water space and the other is connected to steam space in the drum |
| B. | Both ends of the tube are connected to water space |
| C. | One end of the tube is connected to water space and the other end connected to chimney |
| D. | One end of the tube is connected to water space and the other end is connected to superheated steam outlet from superheater |
| E. | One end of the tube is connected to water space and the other is open to atmosphere |
| Answer» B. Both ends of the tube are connected to water space | |
| 294. |
A rope brake dynamometer falls under the category of |
| A. | Transmission type dynamometer |
| B. | Hydraulic dynamometer |
| C. | Mechanical friction type dynamometer |
| D. | Electrical type dynamometer |
| E. | Torsion type dynamometer |
| Answer» D. Electrical type dynamometer | |
| 295. |
Baffles are provided on engines to |
| A. | Improve engine performance |
| B. | Improve heat transfers rate |
| C. | Guard against dirt and dust |
| D. | Assist in starting the engine |
| E. | Reduce fuel consumption |
| Answer» C. Guard against dirt and dust | |
| 296. |
During preliminary test run of an engine for 7 hours cycles if the engine stops after operating for 5 hours then |
| A. | The engine is rejected |
| B. | The engine is again run for 7 hours |
| C. | The engine in run for balance 2 hours |
| D. | The engine is removed and another piece tested |
| E. | None of the above |
| Answer» C. The engine in run for balance 2 hours | |
| 297. |
The gas used for cooling the conductors of large generators is |
| A. | Nitrogen |
| B. | Air |
| C. | Oxygen |
| D. | Carbon dioxide |
| E. | Hydrogen |
| Answer» F. | |
| 298. |
Prony brake is used for testing of |
| A. | Slow speed engines |
| B. | Large engines |
| C. | Small engines |
| D. | High speed engines |
| E. | Engines having small flywheel |
| Answer» D. High speed engines | |
| 299. |
In closed cooling system |
| A. | Hot water is recirculated after cooling |
| B. | Constant fresh water for cooling is supplied |
| C. | Water surrounding the cylinder is allowed to evaporate |
| D. | Air and water cooling is simultaneously used |
| E. | Water does not flow |
| Answer» B. Constant fresh water for cooling is supplied | |
| 300. |
The enthalpy of vaporisation is minimum at |
| A. | 100?C |
| B. | Critical temperature |
| C. | 0?C |
| D. | 25 to 30 |
| E. | Absolute zero |
| Answer» C. 0?C | |