McqMate
These multiple-choice questions (MCQs) are designed to enhance your knowledge and understanding in the following areas: Mechanical Engineering .
| 301. |
Which of the following symptoms will not show that the combustion is necessarily complete or not? |
| A. | Presence of free carbon in exhaust |
| B. | Presence of carbon monoxide in the exhaust |
| C. | Presence of oxygen is the exhaust |
| D. | Presence of nitrogen in the exhaust |
| E. | None of the above |
| Answer» D. Presence of nitrogen in the exhaust | |
| 302. |
The turbulence in diesel engine ensures to |
| A. | Increase the compression pressure |
| B. | Reduce the engine vibrations |
| C. | Bring the fuel quickly in contact with air |
| D. | Increase the fuel consumption |
| E. | Increase the volumetric efficiency |
| Answer» C. Bring the fuel quickly in contact with air | |
| 303. |
In a 2-stroke S.I. engine |
| A. | exhaust and transfer (inlet) ports open and cloe simultaneously |
| B. | exhaust port opens 5? before the transfer port and closes 5? after the transfer port |
| C. | exhaust port opens 5? ahead of the transfer port but both ports close simultaneously |
| D. | none of the above |
| E. | None of the above |
| Answer» B. exhaust port opens 5? before the transfer port and closes 5? after the transfer port | |
| 304. |
In a S.I. engine, if the colour of exhaust flame is bluish, transparent, it indicates that the mixture supplied to the engine is |
| A. | Suitable for maximum output |
| B. | Too lean |
| C. | Too rich |
| D. | Chemical correct |
| E. | Most economical |
| Answer» B. Too lean | |
| 305. |
The escape of burned gases from the combustion chamber past the pistons and into the crank case is called |
| A. | Gas-loss |
| B. | Crank case explosion |
| C. | By-pass |
| D. | Blow-by |
| E. | Passed gas |
| Answer» D. Blow-by | |
| 306. |
Which instrument is used to measure specific gravity |
| A. | Thermometer |
| B. | Hydrometer |
| C. | Hydrometer |
| D. | Anemometer |
| E. | None of the above |
| Answer» C. Hydrometer | |
| 307. |
The stationary part of the Wankel engine has an inner contour of |
| A. | elliptical section |
| B. | two lobed epitrochoid section |
| C. | four lobed epitrochoid section |
| D. | none of the above |
| E. | None of the above |
| Answer» B. two lobed epitrochoid section | |
| 308. |
The efficiency of an oil bath type air cleaner is usually |
| A. | 90% |
| B. | 50% |
| C. | 60% |
| D. | 99% |
| E. | 80% |
| Answer» D. 99% | |
| 309. |
LPG mainly consists of |
| A. | Methane and ethane |
| B. | Propane and butane |
| C. | Petrol and diesel |
| D. | Hexane and butadiene |
| E. | None of the above |
| Answer» B. Propane and butane | |
| 310. |
Over heating of a two stroke air cooled engine cannot be due to |
| A. | Incorrect ignition or valve timing |
| B. | Too lean fuel mixture |
| C. | Lack of cylinder jacket cooling water |
| D. | Partly restricted exhaust system |
| E. | Restricted air cleaner |
| Answer» C. Lack of cylinder jacket cooling water | |
| 311. |
The diagram which shows the correct crank positions corresponding to the opening and closing of the valves, is known as |
| A. | indicator diagram |
| B. | value timing diagram |
| C. | axial force diagram |
| D. | None of the above |
| E. | None of the above |
| Answer» B. value timing diagram | |
| 312. |
Which is the Diesel engined vehicle |
| A. | Ambassador Mark II |
| B. | Premier padmini |
| C. | Standard Gazel |
| D. | Maruti |
| E. | None of the above |
| Answer» E. None of the above | |
| 313. |
Executive clutch clearance caused by improper adjustment or wear of sliding sleeve, generally results in |
| A. | Clutch slip |
| B. | Clutch failure to disengage |
| C. | Clutch plate over heating |
| D. | Uneven clutch engagement |
| E. | Any of the above |
| Answer» B. Clutch failure to disengage | |
| 314. |
Balls for a ball bearing are made of |
| A. | Stainless steel |
| B. | Carbon chrome steel |
| C. | High speed steel |
| D. | Mild steel |
| E. | Stainless steel |
| Answer» B. Carbon chrome steel | |
| 315. |
In spark plug the gap between the electrodes is |
| A. | 10 mm |
| B. | around 5 mm |
| C. | around 1 mm |
| D. | less than 1 mm |
| E. | None of the above |
| Answer» D. less than 1 mm | |
| 316. |
The device used to measure the clearance between the valve and tappet of an internal combustion engine is |
| A. | Slip gauge |
| B. | Thickness gauge |
| C. | Feeler gauge |
| D. | Snap gauge |
| E. | Micrometer |
| Answer» C. Feeler gauge | |
| 317. |
The condenser in ignition circuit of an S.I. engine |
| A. | increases the battery voltage |
| B. | decreases the current from battery |
| C. | avoids arcing at contact breaker |
| D. | none of the above |
| E. | None of the above |
| Answer» C. avoids arcing at contact breaker | |
| 318. |
In an automobile the probable cause for dragging brakes could be |
| A. | Lack of clearance |
| B. | Drums out of round |
| C. | Loose wheel bearings |
| D. | Weak retracting spring |
| E. | Any of the above |
| Answer» E. Any of the above | |
| 319. |
When fully charged, the terminal voltage per cell for a battery is |
| A. | 1.5 volts |
| B. | 2.7 volts |
| C. | 1.7 volts |
| D. | 6 volts |
| E. | 12 volts |
| Answer» B. 2.7 volts | |
| 320. |
For the best utilization of fuel, in the engine cylinder, the air supply should be |
| A. | About 10% surplus |
| B. | 15 to 20 percent deficient |
| C. | About 25% surplus |
| D. | 5 to 10 percent deficient |
| E. | Chemically correct |
| Answer» A. About 10% surplus | |
| 321. |
The phenomenon that causes pressure waves resulting in vibration of structure, rough running and melting of piston is |
| A. | detonation |
| B. | pre-ignition |
| C. | knocking |
| D. | none of the above |
| E. | None of the above |
| Answer» A. detonation | |
| 322. |
Bead wires are made of |
| A. | steel |
| B. | copper |
| C. | zinc |
| D. | Aluminium |
| E. | None of the above |
| Answer» A. steel | |
| 323. |
The efficiency of hydraulic braking system is |
| A. | 50 - 60 percent |
| B. | 40 - 50 percent |
| C. | 25 - 40 percent |
| D. | About 90 percent |
| E. | 60 - 70 percent |
| Answer» D. About 90 percent | |
| 324. |
Diesel engines are generally preferred for road transport these days because of low |
| A. | Maintenance cost |
| B. | Operating cost |
| C. | Initial cost |
| D. | Prime cost |
| E. | Manufacturing cost |
| Answer» B. Operating cost | |
| 325. |
Stratification of charge is achieved by |
| A. | use of two or more carburettors |
| B. | locating two spark plugs on a cylinder |
| C. | incorporating an auxiliary chamber |
| D. | combining inlet and exhaust valves into a single unit |
| E. | None of the above |
| Answer» C. incorporating an auxiliary chamber | |
| 326. |
The knocking in S.I. engines can be prevented if the end mixture is having |
| A. | high density |
| B. | medium density |
| C. | low density |
| D. | none of the above |
| E. | None of the above |
| Answer» C. low density | |
| 327. |
The number of plies in a truck tyre is usually |
| A. | 2 |
| B. | 5--8 |
| C. | 8--10 |
| D. | 3 |
| E. | 12--16 |
| Answer» E. 12--16 | |
| 328. |
A four sylinder four stroke petrol engine running at 1000 rpm will have in all how many sparks in one minute? |
| A. | 250 |
| B. | 500 |
| C. | 1000 |
| D. | 2000 |
| E. | None of the above |
| Answer» B. 500 | |
| 329. |
Which one of the following is mounted between the engine and gear box? |
| A. | Propellor shaft |
| B. | Differential gear |
| C. | Reduction gear |
| D. | Clutch |
| E. | None of the above |
| Answer» D. Clutch | |
| 330. |
A thermostat is provided in automobile engines for |
| A. | Controlling the temperature of the piston |
| B. | Regulating the temperature of lubricating oil |
| C. | Regulating the temperature of suction air |
| D. | Regulating the temperature of haust gases. |
| E. | Controlling the temperature of the cooling system |
| Answer» E. Controlling the temperature of the cooling system | |
| 331. |
Bead of a tyre constitutes |
| A. | metal foundations of the tyre |
| B. | side walls of the tyre |
| C. | shoulder region |
| D. | none of the above |
| E. | None of the above |
| Answer» A. metal foundations of the tyre | |
| 332. |
The probable cause for uneven wear of tyres for a truck could be |
| A. | Low tyre pressure |
| B. | Excessive camber |
| C. | Tyres overloaded |
| D. | Incorrect castor |
| E. | Any of the above |
| Answer» E. Any of the above | |
| 333. |
Circumferential grooves on tyres |
| A. | Lessen the danger of skidding |
| B. | Increase load carrying capacity |
| C. | Provide good traction |
| D. | Remove any stones etc. from sticking to the tyre |
| E. | All of the above |
| Answer» A. Lessen the danger of skidding | |
| 334. |
Which one of the following is a correct statement |
| A. | the exhaust valve of a four stoke I.C. engine should open exactly at the end of expansion stroke |
| B. | in actual practice, inlet valve of a four stroke I.C. engine should open exactly at the start of suction stroke |
| C. | the inlet valve remains open approximately for 180? |
| D. | valve overlap is the angle during which both the inlet and exhaust valves remain open simultaneously |
| E. | None of the above |
| Answer» D. valve overlap is the angle during which both the inlet and exhaust valves remain open simultaneously | |
| 335. |
A heat-treated glass generally used in automobiles upon cracking bursts into |
| A. | Sharp edged fragments |
| B. | Small particles |
| C. | Does not disintegrate |
| D. | Either of the above |
| E. | None of the above |
| Answer» B. Small particles | |
| 336. |
In a multi-cylinder engine, missing in one cylinder is likely to result from |
| A. | Clogged exhaust |
| B. | Vapour lock |
| C. | A defective spark plug |
| D. | An overheated engine |
| E. | None of the above |
| Answer» C. A defective spark plug | |
| 337. |
Dirt or gum in fuel nozzle or jets may cause |
| A. | Excessive fuel consumption |
| B. | Uneven engine speed |
| C. | Smoky black exhaust |
| D. | Lack of engine power |
| E. | White exhaust |
| Answer» C. Smoky black exhaust | |
| 338. |
When not in use, the self-discharge of an automobile battery in dry weather is usually |
| A. | 0.5 to 1% |
| B. | 7 to 7.5% |
| C. | Not more than 10% |
| D. | Not more than 15% |
| E. | Any of the above |
| Answer» A. 0.5 to 1% | |
| 339. |
If the cut-off is decreased, the efficiency of Diesel cycle |
| A. | increases |
| B. | decreases |
| C. | is same |
| D. | none of the above |
| E. | None of the above |
| Answer» A. increases | |
| 340. |
Connecting rod is attached to the piston by the |
| A. | Piston pin |
| B. | Rod cap |
| C. | Cap bolt |
| D. | Lower cap |
| E. | Cap roller bearing |
| Answer» A. Piston pin | |
| 341. |
Clutch slippage while clutch is engaged is particularly noticeable |
| A. | During acceleration |
| B. | At low speed |
| C. | While starting the engine |
| D. | During idling |
| E. | During braking |
| Answer» A. During acceleration | |
| 342. |
The function of Diesel feed pump (when ever provided) is to |
| A. | Pump the fuel to the injector |
| B. | Pump the fuel from the tank into the injection pump |
| C. | Send back the fuel from the injector into the tank |
| D. | Pump the oil into the main gallery |
| E. | Pump the fuel from the injection pump to the injector |
| Answer» B. Pump the fuel from the tank into the injection pump | |
| 343. |
In automobile braking system retarders are |
| A. | chemicals which limit the rate of pressure rise in engine |
| B. | chassis components which face wind resistance |
| C. | auxillary brakes which supplement the main brake |
| D. | none of the above |
| E. | None of the above |
| Answer» C. auxillary brakes which supplement the main brake | |
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