MCQOPTIONS
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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.
| 251. |
A choke in the carburetor is |
| A. | kept in closed position when cold starting the engine |
| B. | kept in open position when cold starting the engine |
| C. | not required since carburetor can produce required af ratio during cold starting |
| D. | none of the above |
| Answer» B. kept in open position when cold starting the engine | |
| 252. |
If the equivalence ratio is greater than one then, mixture is |
| A. | lean |
| B. | chemically correct |
| C. | rich |
| D. | perfect |
| Answer» D. perfect | |
| 253. |
The choke is used when engine is |
| A. | cold |
| B. | hot |
| C. | accelerating |
| D. | idling |
| Answer» B. hot | |
| 254. |
Which phase of combustion takes place during expansion stroke |
| A. | ignition lag |
| B. | preparation phase |
| C. | propagation of flame |
| D. | after burning |
| Answer» E. | |
| 255. |
Arrange the phases of combustion in ascending order according to amount heat evolved in each phase |
| A. | ignition lag, after burning, flame propagation |
| B. | ignition lag, flame propagation, after burning |
| C. | after burning, flame propagation, ignition lag |
| D. | after burning, ignition lag, flame propagation |
| Answer» B. ignition lag, flame propagation, after burning | |
| 256. |
RON is calculated at___ |
| A. | low speed and low temperature |
| B. | high speed and low temperature |
| C. | low speed and high temperature |
| D. | high speed and high temperature |
| Answer» B. high speed and low temperature | |
| 257. |
Practical limits of fuel air ratio for combution in SI engines is |
| A. | 0.11 to 0.05 |
| B. | 0.2 to 0.1 |
| C. | 0.05 to 0.033 |
| D. | 0.2 to 0.033 |
| Answer» B. 0.2 to 0.1 | |
| 258. |
Practical limits for air fuel ratio in SI engines provides |
| A. | range of air fuel ratio which gives comfortable working of si engine |
| B. | range of air fuel ratio to get combustion close to stochiometric conditions in si engine |
| C. | range of air fuel ratio for obtaining maximum power in si engine |
| D. | all of the above |
| Answer» C. range of air fuel ratio for obtaining maximum power in si engine | |
| 259. |
The fuction of the choke is to provide |
| A. | lean mixture |
| B. | some mixture |
| C. | rich mixture |
| D. | stoichiometric mixture |
| Answer» D. stoichiometric mixture | |
| 260. |
When choke is closed, suction presssure is applied on |
| A. | air intake |
| B. | nozzle |
| C. | both air intake and nozzle |
| D. | every where |
| Answer» C. both air intake and nozzle | |
| 261. |
mechanical effficiency is the ratio of |
| A. | frictional power to brake power |
| B. | frictional power to indicated power |
| C. | brake power to indicated power |
| D. | indicated power ot frictional power |
| Answer» D. indicated power ot frictional power | |
| 262. |
In ______________ carburetor, pressure drop is kept constant. |
| A. | constant choke carburetor |
| B. | constant vacuum carburetor |
| C. | multiple venturi carburetor |
| D. | multijet carburetor |
| Answer» C. multiple venturi carburetor | |
| 263. |
With increase in compression ratio, flame travels |
| A. | faster |
| B. | slower |
| C. | with same speed |
| D. | with fluctuations |
| Answer» B. slower | |
| 264. |
Effect of spark in SI engines is____ |
| A. | ionisation of gases |
| B. | rise in volume |
| C. | rise in pressure |
| D. | rise in temperature |
| Answer» E. | |
| 265. |
Which of the following are dopes for SI engine fuels |
| A. | tel |
| B. | tml |
| C. | phenol |
| D. | all of the above |
| Answer» E. | |
| 266. |
A dope or additive is a compound when added in fuel have an effect on |
| A. | decreasing compression ratio |
| B. | increasing self ignition temperature |
| C. | anti knock characteristic |
| D. | none of the above |
| Answer» D. none of the above | |
| 267. |
Lean mixture is required during |
| A. | idling and cruising |
| B. | cruising and starting |
| C. | cruising only |
| D. | cruising, starting and idling |
| Answer» D. cruising, starting and idling | |
| 268. |
Pump which provide additional fuel quantity during acceleration is called as |
| A. | liquid pump |
| B. | vapor pump |
| C. | fuel pump |
| D. | acceleration pump |
| Answer» E. | |
| 269. |
The first phase of combustion in SI engine is named as |
| A. | ignition lag |
| B. | preparation phase |
| C. | both a and b |
| D. | none of the above |
| Answer» D. none of the above | |
| 270. |
Fuel quantity in the all the types of carburetors is mainly controlled with the help of which of the following device |
| A. | throat |
| B. | needle valve |
| C. | choke valve |
| D. | throttle valve |
| Answer» E. | |
| 271. |
RON means ____ |
| A. | radical oxygen number |
| B. | research oxygen number |
| C. | radical octane number |
| D. | research octane number |
| Answer» E. | |
| 272. |
For normal power range following air fuel ratio is prefered |
| A. | 22 to 1 |
| B. | 17 to 1 |
| C. | 5 to 1 |
| D. | 2 to 1 |
| Answer» C. 5 to 1 | |
| 273. |
SI engine contains homogeneous mixture of |
| A. | only vaporized fuel and oxygen |
| B. | fuel and air |
| C. | vaporized fuel,air and residual gases |
| D. | vaporized fuel,oxygen and residual gases |
| Answer» D. vaporized fuel,oxygen and residual gases | |
| 274. |
Cruishing range as percentage of designed load refers to |
| A. | 0 to 20 |
| B. | 20 to 75 |
| C. | 80 to 100 |
| D. | none of the above |
| Answer» C. 80 to 100 | |
| 275. |
The choke in automobile meant for supplying |
| A. | lean mixture |
| B. | rich mixture |
| C. | stoichiometric mixture |
| D. | weak mixture |
| Answer» C. stoichiometric mixture | |
| 276. |
A choke in the carburettor is |
| A. | kept in closed closed position when cold starting the engine |
| B. | kept in open position when cold starting the engine |
| C. | not required since the carburettor can produce a:f ratio during cold starting |
| D. | none of the above |
| Answer» B. kept in open position when cold starting the engine | |
| 277. |
Equivalence ratio means |
| A. | actual fuel air ratio to stoichiometric fuel air ratio |
| B. | stoichiometric fuel air ratio to actual fuel air ratio |
| C. | mass of fuel to mass of air |
| D. | mass of air to mass of fuel |
| Answer» B. stoichiometric fuel air ratio to actual fuel air ratio | |
| 278. |
In continuous inlet manifold injection system, the fuel is injected at a pressure of refers to injection of fuel |
| A. | 1.2 bar |
| B. | 1.5 bar |
| C. | 2 bar |
| D. | 3 bar |
| Answer» D. 3 bar | |
| 279. |
In SI engines the flame travels in____ |
| A. | spherical shape |
| B. | circular shape |
| C. | linear direction |
| D. | sinusoidal pattern |
| Answer» B. circular shape | |
| 280. |
If the bonnet space is limited, the carburetor used is |
| A. | updraught |
| B. | downdraught |
| C. | horizontal draught |
| D. | slant draught |
| Answer» D. slant draught | |
| 281. |
Which of the following is not an effect of increased intake temperature? |
| A. | less delay period |
| B. | higher flame speed |
| C. | more knocking tendency |
| D. | does not affect anything |
| Answer» E. | |
| 282. |
Volatile fuels with heating in intake manifolds will |
| A. | decrease volumetric efficiency |
| B. | decrease power output |
| C. | supply rich mixture |
| D. | both a and b |
| Answer» E. | |
| 283. |
Pressure at throat section of venturi in simple carburetor is |
| A. | above atmospheric pressure |
| B. | atmospheric pressure |
| C. | it is any pressure |
| D. | below atmospheric pressure |
| Answer» E. | |
| 284. |
Idle adjust in idling arrangement is used mainly to control the |
| A. | petrol bleed |
| B. | fuel bleed |
| C. | air bleed |
| D. | mixture bleed |
| Answer» D. mixture bleed | |
| 285. |
Rich mixture is required during |
| A. | idling and cruising |
| B. | cruising and acceleration |
| C. | idling and cruising and acceleration |
| D. | idling and acceleration |
| Answer» E. | |
| 286. |
Octane rating is___ |
| A. | measure of fuel resistance to knock in ci engines |
| B. | measure of fuel assistance to knock in si engines |
| C. | measure of fuel assistance to knock in ci engines |
| D. | measure of fuel resistance to knock in si engines |
| Answer» E. | |
| 287. |
Start of second phase in the combustion of SI engine is indicated by |
| A. | separation of velocity line from compression line on p- diagram. |
| B. | constant pressure on p- diagram. |
| C. | fall of pressure p- diagram. |
| D. | separation of combustion curve from motoring curve on p- diagram. |
| Answer» E. | |
| 288. |
Ignition limits in the SI engine depends upon |
| A. | mixture ratio and temperature |
| B. | volumetric efficiency and temperature |
| C. | engine size and volumetric efficiency |
| D. | mixture ratio and engine size |
| Answer» B. volumetric efficiency and temperature | |
| 289. |
Minimum cross section in venturi is caleed as |
| A. | main jet area |
| B. | throat |
| C. | venturi area |
| D. | float |
| Answer» C. venturi area | |
| 290. |
A:F ratio required for low load running in the range of zero to 20% load is, |
| A. | 12 to 14:1 |
| B. | 15 to 17:1 |
| C. | 17 to 20:1 |
| D. | none of the above |
| Answer» B. 15 to 17:1 | |
| 291. |
For full load on S I engine following changes should be made in mixture prparation |
| A. | mixture should be prepared with fuel quantity increased |
| B. | mixture should be prepared with fuel quantity decreased |
| C. | mixture should be prepared with fuel and air quantity decreased |
| D. | mixture should be prepared with fuel and air quantity increased |
| Answer» B. mixture should be prepared with fuel quantity decreased | |
| 292. |
In idling system, the idling port opens in a draft tube of carburetor on |
| A. | venturi side of throttle valve |
| B. | on engine side of throttle valve |
| C. | exactly at the front of throttle valve |
| D. | none of the above |
| Answer» C. exactly at the front of throttle valve | |
| 293. |
In D-MPFI system the quantity sensed is ____ |
| A. | pressure |
| B. | volume |
| C. | temperature |
| D. | mixture flow rate |
| Answer» B. volume | |
| 294. |
MPFI means |
| A. | metal point fuel injection |
| B. | multi point fuel injection |
| C. | metal power fuel injection |
| D. | multiple pin fuel injection |
| Answer» C. metal power fuel injection | |
| 295. |
L-MPFI ststem responds to____ |
| A. | pressure |
| B. | volume |
| C. | temperature |
| D. | flow rate |
| Answer» E. | |
| 296. |
The D-MPFI system responds to vacuum sensed in____ |
| A. | carburettor |
| B. | intake manifold |
| C. | exhaust manifold |
| D. | piston |
| Answer» C. exhaust manifold | |
| 297. |
if the performance of SI engine manufacturer having different capacities sizes and system are to be compared , the common parameter would be |
| A. | engine cylinder diameter |
| B. | b.h.p |
| C. | speed |
| D. | mean effective pressure |
| Answer» E. | |
| 298. |
When SI Engine is idling mixture enrichment is done |
| A. | to produce maximum power which is required during idling. |
| B. | for compensating diluted mixture in the cylinder because of exhaust gases in the cylinder which remains in previous stroke. |
| C. | both a and b |
| D. | none of the above |
| Answer» C. both a and b | |
| 299. |
A:F ratio needed at the time of starting and idling is |
| A. | 11 to 12:1 |
| B. | 13 to 15:1 |
| C. | 16 to 18:1 |
| D. | 18 to 20:1 |
| Answer» B. 13 to 15:1 | |
| 300. |
The mixture requirements during staarting and idling are |
| A. | rich and rich |
| B. | rich and lean |
| C. | lean and lean |
| D. | lean and rich |
| Answer» B. rich and lean | |