With EFI of diesel engines a) sharp start and stop is not possible b) very high injection pressure can be obtained c) sudden cylinder cut-off is impossible d) diagnostic properties are poor

1 Answer

Answer :

Answer: b Explanation: Generally, with EFI of diesel engines very high injection pressure can be obtained.

Related questions

Description : Scavenging air in diesel engine means a. air used for combustion under pressure b. forced air for cooling the cylinder c. burnt air containing products of combustion d. air used for forcing burnt gases out of the engines cylinder during the exhaust stroke

Last Answer : ANSWER d. air used for forcing burnt gases out of the engines cylinder during the exhaust stroke

Description : Mixing of air and fuel in the diesel engine occurs in a. injection pump b. carburetor c. engine cylinder d. inlet manifold

Last Answer : ANSWER c. engine cylinder

Description : Which of the following factors increases the tendency of knocking in the CI engines? (a) Increasing both the r and coolant temperatures (b) Increasing both the speed and the injection advance (c) Increasing the speed, injection advance and coolant temperature (d) Increasing the compression ratio

Last Answer : Ans :c

Description : The probability of knocking in diesel engines is increased by a. High self-ignition temperature. b. Low volatility. c. High viscosity. d. all of the above

Last Answer : ANSWER d. all of the above

Description : For the best results of efficient combustion, high speed diesel engines need an approximate cetane number of a. 100 b. 50 c. 10 d. 5

Last Answer : ANSWER b. 50

Description : The probability of knocking in diesel engines is increased by a. High self-ignition temperature. b. Low volatility. c. High viscosity. d. All of the above

Last Answer : ANSWER d. all of the above

Description : Most high-speed compression engines operate on a. diesel cycle b. Otto cycle c. dual cycle d. Carnot cycle

Last Answer : ANSWER c. dual cycle

Description : In _____________ injection system only one pump is sufficient for multi-cylinder engine. a) air b) mechanical c) compression fuel d) common rail

Last Answer : Answer: d Explanation: None.

Description : A 4S diesel engine, when running at 2000 rpm has an injection duration of 1.5 ms.What is the corresponding of the crank angle in degrees? (a) 18° (b) 9° (c)36° (d) 15°

Last Answer : Ans :a

Description : In a 4 S diesel engine, the term ‘squish’ refers to the (a) Injection of fuel in the precombustion chamber (b) Discharge of gases from the precombustion chamber (c) Entry of air into the combustion chamber (d) Stripping of fuel from the core

Last Answer : Ans :c

Description : Morse test is conducted on the engine to calculate the mechanical efficiency of A. single cylinder CI engine B. single cylinder SI engine C. only on two stroke engines D. multi cylinder engine

Last Answer : ANSWER : D

Description : In compression ignition engines, swirl denotes a. Haphazard motion of the gases in the cylinder b. Rotary motion of the gases in the cylinder. c. Radial motion of the gases in the cylinder. d. None of the above

Last Answer : ANSWER a. Haphazard motion of the gases in the chamber

Description : If one cylinder of a diesel engine receives more fuel than others , then for that cylinder the A. exhaust will be smoky B. scavenging occurs C. exhaust temperature will be high D. engine starts overheating

Last Answer : ANSWER : B

Description : As a result of detonation in Internal combustion engines the following parameter attains very high value. a. peak pressure b. rate of rise of pressure c. rate of rise of temperature. d. peak temperature.

Last Answer : ANSWER b. rate of rise of pressure

Description : Supercharging is essential in A. aircraft engines B. petrol engines C. gas turbines D. diesel engines

Last Answer : ANSWER : A

Description : For the same capacity engines, the compression ratio of diesel engine a. is lower than the compression ratio of SI engine b. is higher than the compression ratio of SI engine c. is same as the compression ratio of SI engine d. cannot say

Last Answer : ANSWER b. is higher than the compression ratio of SI engine

Description : Which of the following statement is not correct with respect to alcohols as alternate fuel in IC engines a) anti-knock characteristics of alcohol is poor b) alcohol contains about half the heat ... /litre c) alcohol does not vaporize as easily as gasoline d) alcohols are corrosive in nature

Last Answer : Answer: a Explanation: Anti-knock characteristics of alcohol is good.

Description : In a morse test for a 2 cylinder, 2 S SI engine, the brake power was 9 kW. Whereas the brake power of individual cylinders with spark cut off were 4.25 kW and 3.75 kW. The mecheffic of the engine is (a) 90% (b) 80% (c) 45.5% (d) 52.5%

Last Answer : Ans :a

Description : Which of the following is compressed in a diesel engine cylinder A. air B. fuel C. air and fuel D. air and lub oil

Last Answer : ANSWER : A

Description : If the performance of diesel engine of different sizes, cylinder dimensions and power rating are to be compared, which of the following parameters can be used for such comparison? (a) Swept volume (b) Air fuel ratio (c) Specific brake fuel consumption (d) Volumetric efficiency

Last Answer : Ans :c

Description : Which of the following medium is compressed in a diesel engine cylinder? a. air b. air and fuel c. air and lubricating oil d. fuel

Last Answer : ANSWER a. air

Description : The thermal efficiency of a diesel cycle having fixed compression ratio with increase in cut-off ratio will a. increase b. decrease c. independent d. increase or decrease depending upon other factors

Last Answer : ANSWER b. decrease

Description : Explain the methods of fuel injection used EFI system.

Last Answer : Methods of fuel injection: 1. Sequential fuel injection. (SFI) 2. Grouped fuel injection. 3. Simultaneous fuel injection. 4. Continuous injection. 1. Simultaneous Injection: Injection of fuel ... of the fuel injection is determined by ECU depending upon load and speed. 

Description : The tendency of knocking in CI engine reduces by (a) High self ignition temperature of fuel (b) Decrease in jacket water temperature (c) Injection of fuel just before TDC (d) Decrease in injection pressure

Last Answer : Ans :c

Description : If petrol is used in a diesel engine a. higher knocking will occur b. efficiency will be low c. low power will be obtained d. black smoke will be produced

Last Answer : ANSWER a. higher knocking will occur

Description : In electronic fuel injection, there is improvement in the _____________ efficiency due to comparatively less resistance in the intake manifolds which will cause less pressure losses. a) mechanical b) volumetric c) overall d) none of the mentioned

Last Answer : Answer: b Explanation: In electronic fuel injection, there is improvement only in the volumetric efficiency due to comparatively less resistance in the intake manifolds which will cause less pressure losses and no other efficiencies are hindered.

Description : The _____________ sensor, senses rotation of engine camshaft for speed and timing of injection. a) throttle position b) manifold pressure c) camshaft position d) knock

Last Answer : Answer: c Explanation: The camshaft position sensor, senses rotation of engine camshaft for speed and timing of injection whereas the throttle position sensor, senses the movement of the throttle ... engine intake manifold so that the mixture strength can be adjusted with changes in engine load.

Description : For a two stage compressor, the ratio of diameter of low pressure cylinder to high pressure cylinder is equal to A. Square of the ratio of final pressure to initial pressure B. The ratio of ... final pressure to initial pressure D. Cube root of the ratio of final pressure to initial pressure

Last Answer : ANSWER : C

Description : In multi stage compressor, the isothermal compression is achieved by A. Employing intercooler B. By constantly cooling the cylinder C. By running compressor at very slow speed D. By insulating the cylinder

Last Answer : ANSWER : C

Description : Alcohols alone cannot be used in CI engines as a) their self ignition temperature is high b) latent heat of vaporization is high c) all of the mentioned d) none of the mentioned

Last Answer : Answer: c Explanation: None.

Description : An engine indicator is used to determine the following a. Speed. b. Temperature. c. Volume of cylinder. d. Mean effective pressure and Indicated horse power.

Last Answer : ANSWER d. Mean effective pressure and Indicated horse power.

Description : Keeping other parameters constant brake power of diesel engine can be increased by (a) Decreasing the density of intake air (b) Increasing the temperature of intake air (c) Increasing the pressure of intake air (d) Decreasing the pressure of intake air

Last Answer : Ans : c

Description : The fuel in diesel engine is normally injected at pressure of a. 5-10 kg/cm2 b. 20-25 kg/cm2 c 60-80 kg/cm2 d. 90-130 kg/cm2

Last Answer : ANSWER d. 90-130 kg/cm2

Description : For the same peak pressure and heat input a. Otto cycle is more efficient b. Diesel cycle is more efficient c. Both are equally efficient d. None of the above

Last Answer : ANSWER b. Diesel cycle is more efficient

Description : For the same maximum pressure and temperature, what is the relation among the efficiencies of the Otto cycle, the Diesel cycle and the Dual cycle? a. ηDual >ηDiesel >ηOtto b. ηDiesel >ηDual >ηOtto c. ηDiesel >ηOtto >ηDual d. ηOtto >ηDiesel >ηDual

Last Answer : ANSWER b. ηDiesel >ηDual >ηOtto

Description : In which of the following cycle heat is added at constant pressure? a. Otto cycle b. Diesel cycle c. Dual cycle d. Carnot cycle

Last Answer : Answer b. Diesel cycle

Description : Solid injection in CI engine means injection of A. solid fuel only B. liquid fuel only C. liquid fuel and air D. solid fuel and air

Last Answer : ANSWER : B

Description : Solid injection is also called ________________ a) air injection b) mechanical injection c) compression fuel injection d) none of the mentioned

Last Answer : Answer: b Explanation: Generally, solid injection is also called mechanical injection.

Description : Removal of air from the pipeline is termed as ____________ in injection system. a) bleeding b) wound c) sweating d) none of the mentioned

Last Answer : Answer: a Explanation: Generally, the removal of air from the pipeline is termed as bleeding in injection system.

Description : The methods used on fuel injection are : a) air injection b) mechanical injection c) solid fuel injection d) all of the mentioned

Last Answer : Answer: d Explanation: The methods used on fuel injection are air injection, mechanical injection and solid fuel injection.

Description : Continuous injection system usually has a) plunger pump b) rotary pump c) gear pump d) vane pump

Last Answer : Answer: b Explanation: In common use continuous injection system usually has rotary pump.

Description : Common rail injection system uses injection pressures of the order a) 100-200 bar b) 200-400 bar c) 400-600 bar d) 1500 bar

Last Answer : Answer: d Explanation: Generally, common rail injection system uses injection pressures of the order 1500 bar.

Description : D-MPFI system uses a) port injection b) direct injection c) manifold injection d) throttle body injection

Last Answer : Answer: b Explanation: D-MPFI system uses direct injection and L-MPFI system uses port injection while multipoint fuel injection system uses port injection and throttle body injection.

Description : L-MPFI system uses a) port injection b) direct injection c) manifold injection d) throttle body injection

Last Answer : Answer: a Explanation: L-MPFI system uses port injection while multi-point fuel injection system uses port injection and throttle body injection while D-MPFI system uses direct injection.

Description : The process of breaking up a liquid into fine droplets by spraying is called a. vaporization b. carburetion c. injection d. atomization

Last Answer : ANSWER d. atomization

Description : Rate of burning in the compression ignition engine can be controlled by a. rate of injection of fuel b. rate of air taken into carburetor c. both a. and b. d. none of the above

Last Answer : ANSWER a. rate of injection of fuel

Description : Motoring test is conducted on IC engines to determine A. brake power B. indicated power C. friction power D. fuel consumption at full load

Last Answer : ANSWER : C

Description : In spark ignition engines, the knocking tendency can be decreased by a) decreasing compression ratio b) controlling intake throttle c) controlling ignition timing d) adding dopes like tetraethyl lead and ethylene dibromide

Last Answer : Answer: d Explanation: None.

Description : For C.I. engines fuel most preferred are a) aromatics b) paraffins c) olefins d) napthenes

Last Answer : Answer: b Explanation: For C.I. engines fuel most preferred are paraffins and for S.I. engines fuel most preferred are aromatics.

Description : For S.I. engines fuel most preferred are a) aromatics b) paraffins c) olefins d) napthenes

Last Answer : Answer: a Explanation: For S.I. engines fuel most preferred are aromatics while for C.I. engines fuel most preferred are paraffins.