MCQOPTIONS
Saved Bookmarks
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.
| 301. |
Vapour lock is |
| A. | Seizure of supply of fuel in a diesel engine |
| B. | Serious restriction to the supply of fuel due to excessively rapid formation of vapour in S.I. engine |
| C. | Locking of carbourettor jets due to vapour formation |
| D. | Locking of jets due to impurities in petrol |
| E. | None of the above |
| Answer» C. Locking of carbourettor jets due to vapour formation | |
| 302. |
Which of the following is not needed in case of magneto ignition? |
| A. | Coil |
| B. | Capacitor |
| C. | Distributor |
| D. | Battery |
| E. | Spark plug |
| Answer» E. Spark plug | |
| 303. |
Compression ratio for diesel engines is generally in the range |
| A. | 25 to 30 |
| B. | 5 to 10 |
| C. | 22 to 25 |
| D. | 14 to 22 |
| E. | 10 to 14 |
| Answer» E. 10 to 14 | |
| 304. |
Piston ring are plated with chromium, cadmium or phosphate to |
| A. | Reduce wear and eliminate scuffing |
| B. | Improve heat transfer |
| C. | Improve surface finish |
| D. | Prevent clogging |
| E. | Reduce clearance, between rings and cylinder |
| Answer» B. Improve heat transfer | |
| 305. |
In thermodynamics spontaneous processes are those |
| A. | Where a difference is observed in any microscopic property of the system between different times or 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» D. Which require an agency outside the system to force the process | |
| 306. |
In a system if base load is same as maximum demand, the load factor will be |
| A. | 1 |
| B. | 1 percent |
| C. | 0.5 percent |
| D. | Infinity |
| E. | Zero |
| Answer» B. 1 percent | |
| 307. |
Clapeyron equation is applicable |
| A. | To systems in equilibrium |
| B. | To change of boiling point |
| C. | To change of melting point |
| D. | For change of state when two phases are in equilibrium |
| E. | All of the above |
| Answer» E. All of the above | |
| 308. |
In a pumping installation the suction line is is 4 metre long and suction pipe diameter is 100 mm. Now if the suction pipe is replaced by a pipe combination consisting of 2 metres of 100 mm diameter pipe joined with 2 metres of 150 mm diameter pipe, the suction heat will become |
| A. | 6 metres |
| B. | 4 metres |
| C. | 2 metres |
| D. | 1 metre |
| E. | None of the above |
| Answer» C. 2 metres | |
| 309. |
In case of pressure compounded impulse turbine, for the steam while flowing through the nozzle of second stage |
| A. | Pressure drops while velocity increases |
| B. | Pressure increases while velocity decreases |
| C. | Pressure and velocity both increase |
| D. | Pressure increases |
| E. | Pressure and velocity both decrease |
| Answer» B. Pressure increases while velocity decreases | |
| 310. |
Volume of air at 27?C is 2 cu-m. What will be the volume at 327?C |
| A. | 3 cm-m |
| B. | 12 cm-m |
| C. | 4 cu-m |
| D. | 2 cu-m |
| E. | 8 cu-m |
| Answer» D. 2 cu-m | |
| 311. |
Which spark plug will have lower heat rating |
| A. | W 350 T1 |
| B. | W 300 T1 |
| C. | W 95 T1 |
| D. | W 145 T1 |
| E. | W 225 T1 |
| Answer» D. W 145 T1 | |
| 312. |
The power for the propulsion of ship is provided by |
| A. | Diesel engines |
| B. | Steam turbines |
| C. | Either (A) and (B) above |
| D. | Batteries |
| E. | Any of the above |
| Answer» D. Batteries | |
| 313. |
For diatomic gas flowing through a nozzle the critical pressure ratio is given by |
| A. | 0.75 |
| B. | 1 |
| C. | 3.546 |
| D. | 0.528 |
| E. | 0.577 |
| Answer» D. 0.528 | |
| 314. |
As per IS specifications the endurance test for engines is conducted for |
| A. | 500 hours |
| B. | 1000 hours |
| C. | 100 hours |
| D. | 300 hours |
| E. | 200 hours |
| Answer» B. 1000 hours | |
| 315. |
Suri-transmission is |
| A. | hydro-mechanical |
| B. | mechanical-electrical |
| C. | Carbon dioxide |
| D. | electro-pneumatic |
| E. | hydro-pneumatic |
| Answer» B. mechanical-electrical | |
| 316. |
The steam trap is used to |
| A. | Superheat the steam |
| B. | Separate condensate from steam |
| C. | Convert superheated steam into the steam |
| D. | Condense the steam |
| E. | Add moisture to steam |
| Answer» C. Convert superheated steam into the steam | |
| 317. |
Capacitor kVA required to bring the power factor of a 500 kW load 70% to 85% would be |
| A. | 100 kVA |
| B. | 250 kVA |
| C. | 300 kVA |
| D. | 150 kVA |
| E. | 200 kVA |
| Answer» F. | |
| 318. |
Standard air is air at |
| A. | Atmospheric conditions at any specific location |
| B. | 1 kg/cm2 and atmospheric temperature (Relative humidity of 64%) |
| C. | 1 kg/cm2 and 20?C (Relative humidity of 36%) |
| D. | 1 kg/cm2 and 0?C (Relative humidity of 36%) |
| E. | None of the above |
| Answer» B. 1 kg/cm2 and atmospheric temperature (Relative humidity of 64%) | |
| 319. |
Morse test is conducted on |
| A. | Multi-cylinder engines |
| B. | Vertical engines |
| C. | Horizontal engines |
| D. | Vet engines |
| E. | Single cylinder engines |
| Answer» B. Vertical engines | |
| 320. |
In a compression ignition engine higher combustion chamber wall temperature will |
| A. | Reduce knocking tendency |
| B. | Increase knocking tendency |
| C. | Have no effect |
| D. | Reduce exhaust temperature |
| E. | None of the above |
| Answer» B. Increase knocking tendency | |
| 321. |
A cold short metal is |
| A. | One that can not be heated above 500?C |
| B. | One that cannot be welded |
| C. | One that cannot be worked under the hammer or by rolling or bent when cold without racking at the edges |
| D. | One that cannot be easily rolled or bent at low temperatures |
| E. | None of the above |
| Answer» C. One that cannot be worked under the hammer or by rolling or bent when cold without racking at the edges | |
| 322. |
Which of the following functions reduces the irreversibility of a cycle? |
| A. | high speed operation |
| B. | low exhaust pressures |
| C. | regeneration |
| D. | use of lower pressure |
| E. | Carbon dioxide |
| Answer» D. use of lower pressure | |
| 323. |
More test is conducted on |
| A. | Engines with two flywheels |
| B. | Multi-cylinder engines |
| C. | Single cylinder engines |
| D. | High speed engines |
| E. | Slow speed engines |
| Answer» C. Single cylinder engines | |
| 324. |
The efficiency of a jet propulsion unit is generally high at altitudes of |
| A. | 7500 metres |
| B. | 1000 metres |
| C. | 5000 metres |
| D. | 9000 metres |
| E. | More than 10,000 metres |
| Answer» F. | |
| 325. |
In oil burners air is supplied |
| A. | To assist inflow of oil |
| B. | To prevent clogging of burner |
| C. | To improve combustion efficiency |
| D. | To uniformly spray oil in combustion chamber |
| E. | None of the above |
| Answer» D. To uniformly spray oil in combustion chamber | |
| 326. |
Isolate the factor on which bursting pressure of boiler does not depend |
| A. | Tensile strength of the shell |
| B. | Thickness of the shell |
| C. | Diameter of the shell |
| D. | Shear strength of shell material |
| E. | None of the above |
| Answer» E. None of the above | |
| 327. |
Total solid impurities in feed water for a boiler depend upon |
| A. | Boiler pressure |
| B. | Quantity of steam to be generated |
| C. | Type of fuel available |
| D. | Quantity of steam |
| E. | None of the above |
| Answer» B. Quantity of steam to be generated | |
| 328. |
When a receiver is provided in a compound engine, it can be concluded that |
| A. | The engine is non-condensing type |
| B. | The engine is condensing type |
| C. | The cranks are at 90? to each other |
| D. | The cranks are at 180? to each other |
| E. | None of the above |
| Answer» D. The cranks are at 180? to each other | |
| 329. |
In a four stroke engine if a valve opens 25? before B.D.C. and closes 10? after T.D.C. the valve should be |
| A. | Puppet valve |
| B. | Cam valve |
| C. | Spring valve |
| D. | Inlet valve |
| E. | Exhaust valve |
| Answer» F. | |
| 330. |
The thermal efficiency of steam turbine can be increased by |
| A. | Increasing the pressure range |
| B. | Reheating |
| C. | Regeneration |
| D. | All of the above |
| E. | None of the above |
| Answer» E. None of the above | |
| 331. |
Consumption of diesel in a diesel engine per BHP per hour is in the range |
| A. | 185-210 gm |
| B. | 215-300 gm |
| C. | 500-800 gm |
| D. | 100-150 gm |
| E. | 150-180 gm |
| Answer» B. 215-300 gm | |
| 332. |
For the same temperature limits and heat input, the most efficient cycle is |
| A. | Carnot |
| B. | Otto |
| C. | Diesel |
| D. | Brayton |
| E. | All of the above have same efficiency |
| Answer» B. Otto | |
| 333. |
For same output and same compression ratio four stroke SI engines as compared to two stroke engines have |
| A. | Higher fuel consumption |
| B. | Lower thermal efficiency |
| C. | Higher thermal efficiency |
| D. | Higher exhaust temperatures |
| E. | None of the above |
| Answer» D. Higher exhaust temperatures | |
| 334. |
In a reaction turbine which steam flows through the moving blades |
| A. | Pressure reduces while velocity increases |
| B. | Both velocity as well as pressure decreases |
| C. | Pressure increases |
| D. | Pressure increases while velocity reduces |
| E. | Velocity increases |
| Answer» C. Pressure increases | |
| 335. |
If the air clearance is removed in a carburettor engine the fuel air ratio will be |
| A. | Higher |
| B. | Lower |
| C. | Not affected |
| D. | Fluctuating |
| E. | None of the above |
| Answer» C. Not affected | |
| 336. |
Which of the following part is not common between a steam engine and a petrol engine? |
| A. | Crankshaft |
| B. | Connecting road |
| C. | Piston rings |
| D. | Muffler |
| E. | Piston |
| Answer» E. Piston | |
| 337. |
A fan is being used under certain known conditions. If the speed of fan is doubled the air displaced by the fan |
| A. | Will remain the same |
| B. | Will be doubled |
| C. | Will be four times the original displacement |
| D. | will be either times the original displacement |
| E. | None of the above |
| Answer» C. Will be four times the original displacement | |
| 338. |
An air fuel ratio 8 will have |
| A. | Chemically correct air |
| B. | Excess fuel |
| C. | Excess air |
| D. | Any of above |
| E. | None of above |
| Answer» C. Excess air | |
| 339. |
The ideal output velocity of steam from a nozzle having an enthalpy drop of 100 kcal/kg will be |
| A. | 1098 m/s |
| B. | 1000 m/s |
| C. | 600 m/s |
| D. | 915 m/s |
| E. | 789 m/s |
| Answer» E. 789 m/s | |
| 340. |
The maximum horse power of Fiat engine is around |
| A. | 11 |
| B. | 15 |
| C. | 40 to 50 |
| D. | 25 to 30 |
| E. | 60 to 80 |
| Answer» D. 25 to 30 | |
| 341. |
The intercept of Willian's line on Y-axis at the origin, gives |
| A. | Missing quantity |
| B. | Frictional horse power |
| C. | No load steam consumption |
| D. | Idling speed |
| E. | All of the above |
| Answer» E. All of the above | |
| 342. |
In a petrol engine fuel lock generally occurs in |
| A. | suction manifold |
| B. | Carbon dioxide |
| C. | inlet valve |
| D. | Pump |
| E. | gauge lines |
| Answer» E. gauge lines | |
| 343. |
During idling in a compression ignition engine the air fuel ratio may be of the order of |
| A. | 5 |
| B. | 20 |
| C. | 10 |
| D. | 15 |
| E. | 30 |
| Answer» F. | |
| 344. |
During detonation in a petrol engine |
| A. | The rate of speed variation is high |
| B. | The rate of exhaust discharge is high |
| C. | The rate of temperature rise is high |
| D. | The rate of pressure rise is high |
| E. | None of the above |
| Answer» E. None of the above | |
| 345. |
Forced circulation of water does not take place in which of the following boiler? |
| A. | Benson boiler |
| B. | La Mont boiler |
| C. | Babcock and Wilcox boiler |
| D. | Lancashire boiler |
| E. | Velox boiler |
| Answer» E. Velox boiler | |
| 346. |
Diesel engine has air fuel ratio of 30 ; 1 during idling. A petrol engine can also work on such mixture provided |
| A. | Ignition timing is changed |
| B. | Carburettor is modified |
| C. | Dannot run as it is impossible |
| D. | Runs smoothly at lower speeds only |
| E. | Engine is suitably modified |
| Answer» D. Runs smoothly at lower speeds only | |
| 347. |
Compression ratio in case of gas engines waries in the range |
| A. | 10 to 15 |
| B. | 5 to 10 |
| C. | 24 to 30 |
| D. | 20 to 24 |
| E. | 15 to 20 |
| Answer» C. 24 to 30 | |
| 348. |
A petrol engine as compared to diesel engine (both running at full load) is |
| A. | More efficient |
| B. | Less efficient |
| C. | Equally efficient |
| D. | Depend on other factors |
| E. | None of the above |
| Answer» C. Equally efficient | |
| 349. |
Safety valve generally used on high pressure boiler is |
| A. | Dead weight type |
| B. | Lever type |
| C. | Combination lever and spring type |
| D. | Spring type |
| E. | None of the above |
| Answer» E. None of the above | |
| 350. |
Which of the following needs constant cleaning in a diesel engine? |
| A. | Air only |
| B. | Fuel only |
| C. | Air, fuel and lubricating oil |
| D. | Lubricating oil only |
| E. | Air and fuel only |
| Answer» D. Lubricating oil only | |