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.
| 351. |
Which variety of coal has low calorific value? |
| A. | Steam coal |
| B. | Bituminous coal |
| C. | Lignite |
| D. | Anthracite |
| E. | None of the above |
| Answer» D. Anthracite | |
| 352. |
During regenerative feed heating |
| A. | Part of the steam is generated in turbine |
| B. | Condenser is supplied with dry and staturated steam |
| C. | Part of the steam is bled from turbine for feed water heating |
| D. | High pressure steam is used to heat low pressure steam coming out of the turbine after expansion |
| E. | None of the above |
| Answer» D. High pressure steam is used to heat low pressure steam coming out of the turbine after expansion | |
| 353. |
Volumetric efficiency of a well designed engine may be in the range |
| A. | 40 to 50 percent |
| B. | 50 to 75 percent |
| C. | 75 to 90 percent |
| D. | Below 40 percent |
| E. | Below 20 percent |
| Answer» D. Below 40 percent | |
| 354. |
During adiabatic compression |
| A. | No heat leaves or enters the system |
| B. | Maximum work is done |
| C. | Specific heat remains constant |
| D. | Temperature remains constant |
| E. | None of the above |
| Answer» B. Maximum work is done | |
| 355. |
In multistage compression, perfect intercooling means |
| A. | Temperature of air at inlet to subsequent stages is equal to initial temperature |
| B. | Temperature of air at inlet to subsequent stages is less than initial temperature |
| C. | Temperature of air at inlet to subsequent stages should be zero |
| D. | Temperature of inlet to subsequent stages should be equal to the final temperature |
| E. | None of the above |
| Answer» B. Temperature of air at inlet to subsequent stages is less than initial temperature | |
| 356. |
A mechanical indicator is used to determine |
| A. | Pumping horse power |
| B. | Indicated horse power |
| C. | IHP - BHP |
| D. | Friction horse power |
| E. | Brake horse power |
| Answer» C. IHP - BHP | |
| 357. |
In automobiles as the speed of vehicle increases the back pressure |
| A. | Increases |
| B. | Reduces |
| C. | Remains unaffected |
| D. | Depends on other factors |
| E. | None of the above |
| Answer» E. None of the above | |
| 358. |
Which one of the following assumptions is not involved while deriving relation for air standard efficiency of Otto cycle? |
| A. | The engine operates at mederate rpm |
| B. | There is always thermal and chemical equilibrium |
| C. | Expansion and compression are adiabatic |
| D. | There is no chemical reaction inside the engine clinder |
| E. | The working fluid is air for which the specific heats are constant |
| Answer» B. There is always thermal and chemical equilibrium | |
| 359. |
Which of the following engine indicator has least inertia effects? |
| A. | Mechanical indicator |
| B. | Farnborough indicator |
| C. | CRO engine indicator |
| D. | All of the above |
| E. | Carbon dioxide |
| Answer» D. All of the above | |
| 360. |
Advantage of a diesel engine over petrol engine is |
| A. | Low fuel consumption at full load as well as part load |
| B. | Smooth operation at all speeds |
| C. | Low compression ratio |
| D. | No detonation problems |
| E. | All of the above |
| Answer» B. Smooth operation at all speeds | |
| 361. |
The battery used in vespa scooter is |
| A. | No battery is used in the scooters |
| B. | Dry-cell type |
| C. | Lead acid type |
| D. | Nickel-iron type |
| E. | Nickel cadmium type |
| Answer» B. Dry-cell type | |
| 362. |
Bagasse is |
| A. | Fibrous portion of sugarcane left after extracting the juice |
| B. | A variety of coal |
| C. | A fuel consisting of wood etc |
| D. | Same as biogas |
| E. | A kind of rice straw |
| Answer» B. A variety of coal | |
| 363. |
Hot spots are |
| A. | Defects in S.I.engines |
| B. | Hottest point within engine cylinder |
| C. | Do not exist in engines |
| D. | The spots where heavier fractions of fuel are vaporised |
| E. | The hottest spots in engines |
| Answer» E. The hottest spots in engines | |
| 364. |
A coal contains 3.5% sulphur by weight, as fired, and all the sulphur may be assumed to go to formation of sulphur dioxide. How many tonnes of SO2 are produced per day of the firing rate is 35 tonnes per hour |
| A. | 54.8 |
| B. | 60.8 |
| C. | 48.8 |
| D. | 58.8 |
| E. | 100 |
| Answer» E. 100 | |
| 365. |
If the boiler chimney emission consists of dense white smoke, then it can be concluded that |
| A. | Coal contains high percentage of sulphur |
| B. | Insufficient air has been supplied for combustion |
| C. | Chemically correct air has been supplied for combustion |
| D. | Excess air has been supplied for combustion |
| E. | Coal contains high percentage of ash |
| Answer» C. Chemically correct air has been supplied for combustion | |
| 366. |
Which one of the following symptoms will not show that combustion is becessary complete. |
| A. | Presence of free carbon in exhaust |
| B. | Presence of carbon monoxide in exhaust |
| C. | Presence of oxygen in exhaust |
| D. | Presence of nitrogen in exhaust |
| E. | All of the above |
| Answer» E. All of the above | |
| 367. |
Air required for complete combustion of 1 kg of carbon is 11.6 kg. If a fuel contains 88.6% Carbon and 11.4% Hydrogen, the air requirement will |
| A. | Will decrease |
| B. | 12 kg |
| C. | Will increase |
| D. | Remain unaltered |
| Answer» E. | |
| 368. |
The total length of 40 mid-ordinates on a simple steam engine indicator diagram is 17 cm. The pressure scale is 0.6 kg/sq-cm. The mean effective pressure would be |
| A. | 1.0 kg/sq-cm |
| B. | 1.7 kg/sq-cm |
| C. | 1.0 kg/sq-cm |
| D. | 10.2 kg/sq-cm |
| E. | None of the above |
| Answer» D. 10.2 kg/sq-cm | |
| 369. |
De-Laval turbine is mostly used |
| A. | For small powers at high speeds |
| B. | For small powers at low speeds |
| C. | For high powers at low speeds |
| D. | For high powers at high speeds |
| E. | None of the above |
| Answer» B. For small powers at low speeds | |
| 370. |
Which of the following is a false statement. A multicylinder diesel engine is missing on one or more cylinders. The cause may be |
| A. | Valve sticky |
| B. | Insufficient fuel supply to cylinders |
| C. | Compression poor |
| D. | Air cleaner plugged |
| E. | Valves leaky |
| Answer» E. Valves leaky | |
| 371. |
If a steam injector lifts the water but fails to force it into the boiler, the trouble may not be due to |
| A. | Combining tube clogged |
| B. | Insufficient steam pressure |
| C. | Sry steam |
| D. | Leake in water pipe |
| E. | Any of the above |
| Answer» D. Leake in water pipe | |
| 372. |
The steam in a boiler drum is always |
| A. | Dry and saturated |
| B. | Wet or dry and saturated |
| C. | Dry |
| D. | Wet |
| E. | Superheated |
| Answer» E. Superheated | |
| 373. |
In a petrol engine as the speed increases |
| A. | The spark intensity has to be increased |
| B. | The spark intensity has to be reduced |
| C. | The spark has to be advanced |
| D. | The spark has to be retarded |
| E. | None of the above |
| Answer» E. None of the above | |
| 374. |
Piston rod is provided in |
| A. | Slow speed steam engines |
| B. | Double acting steam engines |
| C. | High speed steam engines |
| D. | Non-condensing steam engines |
| E. | Condensing steam engines |
| Answer» C. High speed steam engines | |
| 375. |
The overload capacity of diesel engine is usually around |
| A. | 50% |
| B. | Carbon dioxide |
| C. | 1% |
| D. | 25% |
| E. | 10% |
| Answer» F. | |
| 376. |
In thermodynamics, forced processes are those |
| A. | Where a difference is observed in any microscopic property of the system between different times of states |
| B. | Where a difference is observed in any microscopic property of the system between different times or states |
| C. | Which occur in the direction of an intensive property or driving force contained within the system |
| D. | Which require an agency outside the system to force the process |
| E. | None of the above |
| Answer» E. None of the above | |
| 377. |
Which of the following constituent of air has the least proportion? |
| A. | Carbon monoxide |
| B. | Xenon |
| C. | Argon |
| D. | Helium |
| E. | Neon |
| Answer» C. Argon | |
| 378. |
A cross-head has |
| A. | Reciprocating motion |
| B. | Rotory motion |
| C. | Oscillating motion |
| D. | (A) and (B) only |
| E. | (A) and (C) only |
| Answer» B. Rotory motion | |
| 379. |
Free air is air at |
| A. | 1 kg/cm2 and 20?C |
| B. | 1 kg/cm2 and atmospheric temperature |
| C. | 1 kg/cm2 and 27?C |
| D. | 1 kg/cm2 and 0?C |
| E. | Atmospheric conditions at any specific location |
| Answer» F. | |
| 380. |
The work done on a compressor will be least when air is taken from |
| A. | As and where available |
| B. | Source of low temperature air |
| C. | A source at 0?C |
| D. | Atmosphere |
| E. | Source of high temperature air |
| Answer» C. A source at 0?C | |
| 381. |
Which statement is false in case of SI engines |
| A. | Accetylene has least tendency to knocking |
| B. | Adding methyl groups to the side of the carbon chain increases the knocking tendency |
| C. | Unsaturated aliphatic hydrocarbons show less knocking tendency |
| D. | Increasing the length of the carbon chain increases the knocking tendency |
| E. | Centralising the carbon atoms decreases the knocking tendency |
| Answer» B. Adding methyl groups to the side of the carbon chain increases the knocking tendency | |
| 382. |
The temperature of the blades of a gas turbine may be closer to |
| A. | 350?C |
| B. | 212?C |
| C. | 1200?C |
| D. | 600?C |
| E. | 100?C |
| Answer» D. 600?C | |
| 383. |
In cse the exhaust silencer of a petrol engine is partly choked, it is likely to result in |
| A. | Increased compression ratio |
| B. | Increased fuel consumption |
| C. | Reduced fuel consumption |
| D. | Reduced compression ratio |
| E. | None of the above |
| Answer» C. Reduced fuel consumption | |
| 384. |
An average percentage of Carbon and Hydrogen in Petrol may be roughly given as |
| A. | 70% C, 70% H2 |
| B. | 15% C, 85% H2 |
| C. | 50% C, 50% H2 |
| D. | 85% C, 150% H2 |
| E. | 60% C, 40% H2 |
| Answer» E. 60% C, 40% H2 | |
| 385. |
Presence of impurities in ice |
| A. | Does not have any effect |
| B. | Lowers melting point |
| C. | Makes it heavier than water |
| D. | Raises melting point |
| E. | Depends on other factors |
| Answer» C. Makes it heavier than water | |
| 386. |
Which of the following is false statement? The cause of slow cranking of a gas engine during starting may be |
| A. | Partially discharged battery |
| B. | Under capacity battery |
| C. | High air temperature |
| D. | Heavy engine oil |
| E. | Faulty starting motor |
| Answer» D. Heavy engine oil | |
| 387. |
The maximum temperature in a gas turbine is of the order of |
| A. | 700?C |
| B. | 2000?C |
| C. | 2500?C |
| D. | 1500?C |
| E. | 1000?C |
| Answer» B. 2000?C | |
| 388. |
According to Boyle's law |
| A. | At constant pressure the temperature of a gas varies inversely as its volume |
| B. | At constant pressure the absolute temperature of a gas varies inversely as its volume |
| C. | At constant temperature, the pressure of a gas varies inversely as its volume |
| D. | At constant temperature, the absolute pressure of a gas varies inversely as its volume |
| E. | None of the above |
| Answer» E. None of the above | |
| 389. |
Which one of the following is a safety device on a compressor? |
| A. | Intercooler relief valve |
| B. | Over pressure shut down |
| C. | Strainer |
| D. | Over speed shut down |
| E. | Relief valve |
| Answer» F. | |
| 390. |
In case of a condensing turbine the pressure in the last stage of the turbine is |
| A. | Same as atmospheric pressure |
| B. | Slightly above the atmospheric pressure |
| C. | 5 to 6 kg/cm2 above the atmospheric pressure |
| D. | Less than the atmospheric pressure |
| E. | 10 to 12 kg/cm2 above the atmospheric pressure |
| Answer» E. 10 to 12 kg/cm2 above the atmospheric pressure | |
| 391. |
A 'blue' flame is |
| A. | Non-radiant flame |
| B. | Radiant flame |
| C. | Super high temperature flame |
| D. | Ordinary flame in oil burners |
| E. | None of the above |
| Answer» B. Radiant flame | |
| 392. |
The knocking tendency in a compression ignition engine for a given fuel will |
| A. | Enhance by reducing compression ratio |
| B. | Enhance by increasing compression ratio |
| C. | Depend on other factors |
| D. | Increase to certain limits and then no change |
| E. | None of the above |
| Answer» B. Enhance by increasing compression ratio | |
| 393. |
Flash point for diesel fuel oil should be |
| A. | Minimum 49?C |
| B. | Maximum 49?C |
| C. | Maximum 100?C |
| D. | Maximum 200?C |
| E. | None of the above |
| Answer» B. Maximum 49?C | |
| 394. |
An optical pyrometer works on the principle of |
| A. | Expansion of fluids |
| B. | Mono-chromatic radiation |
| C. | Thermo-electric effect |
| D. | Total radiation |
| E. | Change of electrical resistance |
| Answer» C. Thermo-electric effect | |
| 395. |
Air fuel ratio for a jet engine is of the order of |
| A. | 15 ; 1 |
| B. | 20 ; 1 |
| C. | 400 ; 1 |
| D. | 60 ; 1 |
| E. | 10 ; 1 |
| Answer» E. 10 ; 1 | |
| 396. |
Ricardo's theory is associated with |
| A. | Steam turbines |
| B. | Wankel engines |
| C. | Internal combustion engines |
| D. | Closed cycle gas turbines |
| E. | Engine vibrations |
| Answer» D. Closed cycle gas turbines | |
| 397. |
The vapour pressure is related to the enthalpy of vaporization in |
| A. | Maxwell's equation |
| B. | Henry's law |
| C. | Dalton's law |
| D. | Clausius Clapeyron equation |
| E. | Raoult's law |
| Answer» E. Raoult's law | |
| 398. |
A De-Laval turbine is |
| A. | Multiple stage reaction turbine |
| B. | Single rotor impulse turbine |
| C. | Multiple rotor reaction turbine |
| D. | Velocity compounded impulse turbine |
| E. | Single rotor reaction turbine |
| Answer» C. Multiple rotor reaction turbine | |
| 399. |
Naphtha is used as |
| A. | Lubricant for turbines |
| B. | Lubricant for slow speed engines |
| C. | Fuel for marine engines |
| D. | Fuel for furnaces |
| E. | Fuel for aero engines |
| Answer» E. Fuel for aero engines | |
| 400. |
Calorific value of methane gas can be determined by |
| A. | Bomb calorimeter |
| B. | Bunsen's apparatus |
| C. | Orsat's apparatus |
| D. | None of the above |
| E. | At constant temperature |
| Answer» E. At constant temperature | |