MCQOPTIONS
Saved Bookmarks
MCQOPTIONS
This section includes 471 Mcqs, each offering curated multiple-choice questions to sharpen your Uncategorized topics knowledge and support exam preparation. Choose a topic below to get started.
| 401. |
Transient condition of SI engine is I. Starting II. Acceleration III. Idling IV. Deceleration V. Warming up |
| A. | only i and ii |
| B. | only i,ii, iv and v |
| C. | only iii |
| D. | all i,ii,iii,iv and v |
| Answer» C. only iii | |
| 402. |
Engine at the time of starting and idling needs mixture which is, |
| A. | rich |
| B. | chemically correct |
| C. | lean |
| D. | none of the above |
| Answer» B. chemically correct | |
| 403. |
During cruising, mixture provided by simple carburetor is |
| A. | increasingly rich |
| B. | increasingly lean |
| C. | constant chemically correct |
| D. | sometimes rich, sometimes lean |
| Answer» B. increasingly lean | |
| 404. |
Which of the following is not the requirement of a good carburettor? |
| A. | prepare a:f ratio as required during starting, idling, no load running, cruising, maximum power |
| B. | prepare non-homogeneous (heterogeneous) mixture |
| C. | energy is supplied to change fuel from liquid to vapour form |
| D. | supply rich mixture during acceleration |
| Answer» C. energy is supplied to change fuel from liquid to vapour form | |
| 405. |
At low load running (zero to 20% load of rated power) engine requires mixture which is, |
| A. | rich |
| B. | chemically correct |
| C. | lean |
| D. | none of the above |
| Answer» B. chemically correct | |
| 406. |
Venturi in the carburettor results in |
| A. | decrease of air velocity |
| B. | increase of air velocity |
| C. | decrease of fuel flow |
| D. | increase of manifold vacuum |
| Answer» C. decrease of fuel flow | |
| 407. |
Ignition lag in SI engine depends on following parameters |
| A. | only b |
| B. | nature of fuel,pressure and temperature |
| C. | temperature coefficient, proportion of exhaust gases |
| D. | both b and c |
| Answer» E. | |
| 408. |
Ignition lag phase is also |
| A. | mechanical process |
| B. | mechanical and chemical process |
| C. | chemical process |
| D. | none of the above |
| Answer» D. none of the above | |
| 409. |
Flame advancement from the start of formation of first nucleus of combustion depends on |
| A. | temperature of flame front itself, density of surrounding mixture and temperature inside of cylinder. |
| B. | only temperature of flame front itself, |
| C. | temperature of flame front itself and density of surrounding mixture |
| D. | only pressure and temperature inside cylinder |
| Answer» B. only temperature of flame front itself, | |
| 410. |
In SI engines, Maximum flame speed is obtained when equivalance ratio is___ |
| A. | less than 1 |
| B. | between 1 to 1.1 |
| C. | between 1.1 to 1.2 |
| D. | greater than 1.2 |
| Answer» D. greater than 1.2 | |
| 411. |
In constant choke carburetor or open choke carburetor ___________ is kept constant. |
| A. | air flow area |
| B. | fuel flow area |
| C. | both air and fuel flow areas |
| D. | pressure drop |
| Answer» D. pressure drop | |
| 412. |
Multi cylinder engines needs air-fuel ratio which is |
| A. | same as single cylinder engines |
| B. | leaner than the single cylinder engines |
| C. | richer than the single cylinder engines |
| D. | always close to stoichiometric conditions |
| Answer» D. always close to stoichiometric conditions | |
| 413. |
In case of simple carburetor for high speed engines too rich mixture is created because of following reason |
| A. | more vacuum at throttle section |
| B. | less air from atmosphere |
| C. | less vacuum at throat |
| D. | too high vacuum at throat |
| Answer» E. | |
| 414. |
During afterburning phase in SI engine crank rotates by about |
| A. | 20 deg. |
| B. | 190 deg. |
| C. | 170 deg. |
| D. | 10 deg. |
| Answer» D. 10 deg. | |
| 415. |
During cold starting problems air fuel ratio required is |
| A. | 30 to 1 |
| B. | 10 to 1 |
| C. | 3 to 1 |
| D. | 2 to 3 |
| Answer» D. 2 to 3 | |
| 416. |
During cold starting problems |
| A. | vaporized fuel in carburetor is condensed in intake manifold, cylinder and piston top |
| B. | vaporized fuel in carburetor is condensed in intake manifold, carburetor itself |
| C. | vaporized fuel in carburetor is condensed in carburetor, cylinder and piston top |
| D. | vaporized fuel in carburetor is condensed in intake manifold, cylinder and carburetor |
| Answer» B. vaporized fuel in carburetor is condensed in intake manifold, carburetor itself | |
| 417. |
During cold starting problems in winter seasons in india |
| A. | throat section is closed |
| B. | choke valve is closed |
| C. | throttle valve is closed |
| D. | main jet is closed |
| Answer» C. throttle valve is closed | |
| 418. |
if n is the rpm, number of power strokes per min in a two stroke engine is |
| A. | n/2 |
| B. | n |
| C. | 2n |
| D. | 4n |
| Answer» C. 2n | |
| 419. |
For Full throttle valve opened condition of an S I engine |
| A. | we get less brake horse power |
| B. | we get only required brake horse power |
| C. | brake horse power is changing |
| D. | we get maximum brake horse power |
| Answer» E. | |
| 420. |
During cruising range of operation of SI engine throttle position is opened by |
| A. | 0 to 20% |
| B. | 20 to 78 % |
| C. | 90 % to 100% |
| D. | all the ranges are suitable |
| Answer» C. 90 % to 100% | |
| 421. |
if the compression ration of otto cycle is 8.18 and brake thermal efficiency of actual cyle is 29.03%........what would be the relative efficienct |
| A. | 0.51109 |
| B. | 0.6103 |
| C. | 0.3105 |
| D. | 0.2908 |
| Answer» B. 0.6103 | |
| 422. |
During no load running of the engine, the throttle valve is kept almost closed. A simple carburetor will provide |
| A. | rich mixture |
| B. | stoichiometric mixture |
| C. | extremely lean mixture |
| D. | none of the above |
| Answer» B. stoichiometric mixture | |
| 423. |
Which is not the drawback of a simple carburettor, |
| A. | it provides required air-fuel ratio at all throttle position |
| B. | it provides increasing richness of a:f ratio as speed increases |
| C. | it provides very lean mixture at low speeds which is not adequate to ignite the mixture |
| D. | all of the above |
| Answer» B. it provides increasing richness of a:f ratio as speed increases | |
| 424. |
brake thermal efficiency of ci engine is about |
| A. | 20-28% |
| B. | 30-40% |
| C. | 40-50% |
| D. | more then 50% |
| Answer» C. 40-50% | |
| 425. |
what would be the compression ratio of the engine if the clearnce volume is 0.065lit and the engine bore is of 70mm and the stroke is of 100mm |
| A. | 5.632 |
| B. | 7 |
| C. | 6.923 |
| D. | 8 |
| Answer» D. 8 | |
| 426. |
Ignition lag, spreading of flame and after burning are the stages observed during combustion in |
| A. | petrol engines |
| B. | diesel engines |
| C. | pi engines |
| D. | turbocharged engines |
| Answer» B. diesel engines | |
| 427. |
for four cylinder four stroke petrol engien the bore is 11cm and stroke is 13cm, running at speed of 2250 rpm. What is the swept volume of the engine |
| A. | 0.18 cubic meter per second |
| B. | 0.25 cubic meter per second |
| C. | 0.37 cubic meter per second |
| D. | none of the above |
| Answer» D. none of the above | |
| 428. |
The combustion of mixture without a flame front is called |
| A. | auto ignition |
| B. | normal |
| C. | abnormal |
| D. | none of the above |
| Answer» B. normal | |
| 429. |
As the speed of flame travel increases, detonation___ |
| A. | increases |
| B. | decreases |
| C. | cant predict |
| D. | remains same |
| Answer» C. cant predict | |
| 430. |
AS distance of flame travel increases, detonation |
| A. | increases |
| B. | decreases |
| C. | cant predict |
| D. | remains same |
| Answer» B. decreases | |
| 431. |
During propagatuion of flame in SI engine crank rotates by about |
| A. | 20 deg. |
| B. | 40 deg. |
| C. | 30 deg. |
| D. | 10 deg. |
| Answer» B. 40 deg. | |
| 432. |
The peak pressure in SI engine will be observed when crank angle is |
| A. | about 10 deg. before tdc |
| B. | about 10 deg. after tdc |
| C. | at tdc |
| D. | at bdc |
| Answer» C. at tdc | |
| 433. |
a four stroke gas engine has a bor of 20cm and stroke of 35 cm . What would be the swept volume of the engine |
| A. | 6863.93 cc |
| B. | 5853.93 cc |
| C. | 5369.93 cc |
| D. | 7853.93 cc |
| Answer» E. | |
| 434. |
if n is theorem, number of power stroke per minute in a four stroke enigne is |
| A. | n/2 |
| B. | n |
| C. | 2n |
| D. | 4n |
| Answer» B. n | |
| 435. |
the air box/ swept volume ratio should be in the range for single cylinder engine |
| A. | 10-100% |
| B. | 200-300% |
| C. | 500-600% |
| D. | 10 |
| Answer» D. 10 | |
| 436. |
The bore and stroke of a single cylinder four stroke engine are 100 mm and 160 mm resp. if the brake torqe is 50NM, the brake mean effective pressure is |
| A. | 5 bar |
| B. | 7-6bar |
| C. | 10bar |
| D. | 15bar |
| Answer» B. 7-6bar | |
| 437. |
what would be the number of powe strokes per min ..? If a six cylinder four stroke engine runs at 233.33 rpm and the number of missed powe stroke is 8.33 per min |
| A. | 105.33 |
| B. | 107.33 |
| C. | 108.66 |
| D. | none of the above |
| Answer» D. none of the above | |
| 438. |
B.P of a four cylinde, four stroke engine is measured by brake dynamometer which develops a torque of 1000N-M at 4200rpm. The B.P is about |
| A. | 440kw |
| B. | 1760kw |
| C. | 4.4x105 kw |
| D. | none of the above |
| Answer» B. 1760kw | |
| 439. |
the air standard efficiecny of engine is 0.42647 and corsponding relative efficiecny is 0.55. what would be the corsponding indicated thermal efficiency |
| A. | 0.2346 |
| B. | 0.4621 |
| C. | 0.3256 |
| D. | 0.3325 |
| Answer» B. 0.4621 | |
| 440. |
what would be the brake thermal efficiency of the engine, if the brake power of the engine is of 58.65KW, fuel consumption is 14kg/hr and the calrofic value of the fuel is 42500kj/kg |
| A. | 0.3548 |
| B. | 0.2578 |
| C. | 0.3898 |
| D. | 0.3696 |
| Answer» B. 0.2578 | |
| 441. |
the brake thermal efficiecny of SI engine is in the range of |
| A. | 35%-60% |
| B. | 25%-35% |
| C. | 60%-80% |
| D. | none of the above |
| Answer» C. 60%-80% | |
| 442. |
When the throttle is suddenly opened, the mixture from the simple carburettor tends to become |
| A. | rich |
| B. | lean |
| C. | stoichiometric |
| D. | not affected |
| Answer» C. stoichiometric | |
| 443. |
a single cylinder four stroke engine having bore 18 cm and stroke 36cm, revolving at 285 rpm and having mean effective pressure 7.2 bar. The indicated power is |
| A. | 7.85kw |
| B. | 31.4kw |
| C. | 15.7kw |
| D. | none of the above |
| Answer» B. 31.4kw | |
| 444. |
a six cylinder four stroke petron engine having a bore of 90 mm and stroke of 100mm and runs at a speed of 2500 rpm. What would be the indicated power |
| A. | 53.239kw |
| B. | 18.368kw |
| C. | 67.593kw |
| D. | 55.235kw |
| Answer» D. 55.235kw | |
| 445. |
a vertical single cylinder four stroke diesel engine has a bore of 80mm and stroke of 100mm resp. it is water cooled and develops a torque of 305 N-m . What is the mean effective pressure ? |
| A. | 2.285 bar |
| B. | 5.875 bar |
| C. | 6.325 bar |
| D. | 7.835 bar |
| Answer» C. 6.325 bar | |
| 446. |
In SI engines, to aviod knock, combustion chamber should have___ |
| A. | small bore |
| B. | large bore |
| C. | large flame path |
| D. | large ratio of flame path to bore |
| Answer» B. large bore | |
| 447. |
If flame travel from point of ignition upto end of combustion chamber without change in speed, the combustion is called |
| A. | auto ignition |
| B. | normal |
| C. | abnormal |
| D. | none of the above |
| Answer» C. abnormal | |
| 448. |
During cold starting problems air-fuel mixture sent to engine is |
| A. | 2 to 3 times normal amount of fuel |
| B. | 5 to 10 times normal amount of fuel |
| C. | 10 to 20 times normal amount of fuel |
| D. | 1 to 2 times normal amount of fuel |
| Answer» C. 10 to 20 times normal amount of fuel | |
| 449. |
With increase in speed, the crank angle required for flame propagation___ |
| A. | increases |
| B. | decreases |
| C. | remains same |
| D. | cant predict |
| Answer» D. cant predict | |
| 450. |
In multi cylinder engines, cylinder close to carburetor receives |
| A. | richer mixture |
| B. | leaner mixture |
| C. | stoichiometric condition mixture |
| D. | none of the above |
| Answer» C. stoichiometric condition mixture | |