McqMate
These multiple-choice questions (MCQs) are designed to enhance your knowledge and understanding in the following areas: Mechanical Engineering .
| 401. |
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» A. Higher | |
| 402. |
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» A. Fixed carbon and heating value | |
| 403. |
Piston rings are made of |
| A. | Aluminium |
| B. | Carbon steel |
| C. | Alloy steel |
| D. | Copper |
| E. | Cast iron |
| Answer» E. Cast iron | |
| 404. |
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» A. To increase the power output of engine | |
| 405. |
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» C. ? 200?C | |
| 406. |
Gusset stays are provided in |
| A. | Steam turbines |
| B. | Steam condensers |
| C. | Chimney |
| D. | Boilers |
| E. | Steam engines |
| Answer» D. Boilers | |
| 407. |
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» D. When burnt in a reversible process | |
| 408. |
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» B. 0.546 | |
| 409. |
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» D. Running at full load and full speed | |
| 410. |
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» D. Friction horse power at cranking r.p.m | |
| 411. |
Water gas is a mixture of |
| A. | CO2 and N2 |
| B. | CO and H2 |
| C. | SO2, CO2 and N2 |
| D. | N2 and H2 |
| E. | CO, CO2 and SO2 |
| Answer» B. CO and H2 | |
| 412. |
A jet engine has |
| A. | Propeller in front |
| B. | Propeller in back |
| C. | One propeller in front and one propeller in back |
| D. | No propeller |
| E. | None of the above |
| Answer» D. No propeller | |
| 413. |
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» D. Between Otto and diesel cycles | |
| 414. |
In isochronous governors the speed drop is |
| A. | 50 percent |
| B. | 75 percent |
| C. | 10 percent |
| D. | 20 percent |
| E. | Zero |
| Answer» E. Zero | |
| 415. |
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» B. Delay period | |
| 416. |
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» D. Coad scales are inaccurate, reading high | |
| 417. |
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» B. Materials spring back or recoil when pressure is removed | |
| 418. |
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» A. Is quantity of heat required to raise temperature of one tonne of water from 14.5?C to 15.5?C | |
| 419. |
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» B. At the foot of the chimney | |
| 420. |
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» E. To minimise the work of compression | |
| 421. |
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» A. Creep | |
| 422. |
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» C. That heat which produces a rise of temperature | |
| 423. |
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» B. decrease in cut off | |
| 424. |
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» D. Admission pressure is varied while cut off remains unaltered | |
| 425. |
For gas turbines compressors used are |
| A. | Centrifugal type |
| B. | Lobe type |
| C. | Axial flow type |
| D. | Sliding vane type |
| E. | Reciprocating type |
| Answer» C. Axial flow type | |
| 426. |
How many kg of air will contain one kg of oxygen? |
| A. | 6.65 kg |
| B. | 10 kg |
| C. | 4.35 kg |
| D. | 12.5 kg |
| E. | 1 kg |
| Answer» C. 4.35 kg | |
| 427. |
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» B. Serious restriction to the supply of fuel due to excessively rapid formation of vapour in S.I. engine | |
| 428. |
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» D. Muffler | |
| 429. |
The efficiency of a jet engine is higher at |
| A. | Higher altitudes |
| B. | Lower altitudes |
| C. | High speeds |
| D. | High speeds and low altitudes |
| E. | Low speeds |
| Answer» A. Higher altitudes | |
| 430. |
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» A. Unequal distribution of mixture | |
| 431. |
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» D. Feed water for boiler | |
| 432. |
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» C. Which occur in the direction of an intensive property or driving force contained within the system | |
| 433. |
Which one of the following is not a constituent of coal |
| A. | Carbon |
| B. | Manganese |
| C. | Inorganic matter |
| D. | Hydrogen |
| E. | Nitrogen |
| Answer» B. Manganese | |
| 434. |
The gas used for cooling the conductors of large generators is |
| A. | Nitrogen |
| B. | Air |
| C. | Oxygen |
| D. | Carbon dioxide |
| E. | Hydrogen |
| Answer» E. Hydrogen | |
| 435. |
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» B. The engine is again run for 7 hours | |
| 436. |
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» C. Small engines | |
| 437. |
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» C. Reducing the speed of the engine | |
| 438. |
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» C. At constant volume | |
| 439. |
The maximum horse power of a 150 CC scooter engine is around |
| A. | 3 |
| B. | 1.5 |
| C. | 15 |
| D. | 8 |
| E. | 33 |
| Answer» D. 8 | |
| 440. |
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» E. Spreader stokers | |
| 441. |
The enthalpy of vaporisation is minimum at |
| A. | 100?C |
| B. | Critical temperature |
| C. | 0?C |
| D. | 25 to 30 |
| E. | Absolute zero |
| Answer» B. Critical temperature | |
| 442. |
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» A. Blades | |
| 443. |
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» A. One end of the tube is connected to water space and the other is connected to steam space in the drum | |
| 444. |
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» B. Improve heat transfers rate | |
| 445. |
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» C. Mechanical friction type dynamometer | |
| 446. |
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» A. Fuel stored to meet day's requirement for the boiler | |
| 447. |
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» A. Hot water is recirculated after cooling | |
| 448. |
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» B. Intake valve closes after BDC | |
| 449. |
Coking is |
| A. | In boiler furnace some coal becomes plastic and forms lumps or masses of coke |
| B. | Making cakes of coal out of fine powders |
| C. | Coal produced from burning of wood in inert atmosphere |
| D. | Free burning coals are known as coking coals |
| E. | None of the above |
| Answer» A. In boiler furnace some coal becomes plastic and forms lumps or masses of coke | |
| 450. |
Shock effect in the nozzle generally occurs in |
| A. | Inlet |
| B. | Converging section |
| C. | Throat |
| D. | Diverging section |
| E. | Exit |
| Answer» D. Diverging section | |
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