Description : A two stroke engine has a speed of 750 rpm. A four stroke engine having an identical cylinder size runs at 1500 rpm. The theoretical output of the two stroke engine will (a) Be twice that of the four stroke ... ) Be the same as that of the four stoke (d) Depend upon whether it is a CI or SI engine
Last Answer : Ans :c
Description : Whenthecrankshaft of 4-stroke running at 1500 rpm thecamshaftwillrun at A. 3000 rpm B. 6000 rpm C. 1500 rpm D. 750 rpm
Last Answer : ANSWER : D
Description : In a typical medium speed 4- stroke Diesel engine, the inlet valve A. opens 20°before top dead centre and closes at 35°afterthebottomdead centre. B. opens up at top dead centre and closes at bottomdead centre C. may open orcloseanywhere D. remains open for 200°
Last Answer : ANSWER : A
Description : The actual volume of fresh charge admitted in 4-stroke petrol engine is A. equal to stroke volume B. equal stroke volume and clearance volume C. less than stroke volume D. more than stroke volume
Last Answer : ANSWER : C
Description : The domestic refrigerator uses following type of compressor (a) centrifugal (b) axial (c) miniature sealed unit (d) piston type reciprocating
Last Answer : Ans: d
Description : In a naturally aspirated diesel engine, the air is supplied by a A. supercharger B. centrifugal pump C. movement of engine piston D. reciprocating pump
Description : The energy of expanding gas is transferred by piston to connecting rod through a. Crank pin b. Gudgeon pin c. Bearing d. Crankcase (Ans:b)
Last Answer : Which of the following is not used in four stroke compression-ignition (CI) engines? a. Fuel pump b. Spark plug c. Fuel injector d. Inlet and outlet Valves (Ans:b)
Description : A reciprocating compressor is not suitable for use as a supercharger because: A. it runs at lower rpm B. the pressure ratio is high C. volumetric efficiency is high D. it is bulky and can handle small quantity of air
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 : Detonation can be controlled by a. varying the compression ratio b. using lean mixture c. retarding the spark timing d. reducing the rpm
Last Answer : ANSWER c. retarding the spark timing
Description : In two stroke engine one power occurs in _______ of crank rotation A. 180° B. 360° C. 270° D. 720°
Last Answer : ANSWER : B
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
Description : In four stroke engine which of the following is also known as power stroke a. Suction stroke b. Compression stroke c. Expansion stroke d. Exhaust stroke (Ans:c) Measurements of fuel and air ... into IC engine,___________its efficiency A. increase B. decrease C. does not alter D. unpredictable on
Description : In four stroke engine there is one power stroke in _____ of crankshaft rotation. a. 180° b. 360° c. 540° d. 720° (Ans:d)
Last Answer : The ascending order of strokes in four stroke engine is a. Suction stroke - Expansion stroke - Compression stroke - Exhaust stroke b. Suction stroke - Compression stroke - Expansion stroke -Exhaust ... stroke d. Suction stroke - Compression stroke - Exhaust stroke - Expansion stroke (Ans:b)
Description : In two stroke engine, which of the following functions are performed at the same time? a. Compression and exhaust b. Intake and Expansion c. Intake and exhaust d. Intake and compression (Ans:c)
Last Answer : The compression ratio in a Compression Ignition (CI) engine is generally in between a. 8 to 13 b. 14 to 23 c. 20 to 28 d. 25 to 32 (Ans:b)
Description : Fuel is injected into the cylinder at the end of ______________ stroke. a) suction b) compression c) expansion d) exhaust
Last Answer : Answer: b Explanation: Fuel is injected into the cylinder at the end of compression stroke and not at suction or expansion stroke.
Description : For same power output and same r, as compared to 2- stroke engines, four stroke SI engines have (a) Higher fuel consumption (b) Lower thermal efficiency (c) Highest exhaust temperatures (d) Higher thermal efficiency
Last Answer : Ans :d
Description : A gas engine has a volume of 300 cc and clearance volume of 25 cc. Its volumetric efficiency is 0.8 and mech efficiency is 0.9. What is the volume of the mixture taken in per stroke? (a) 248 cc (b) 252 cc (c) 264 cc (d) 286 cc
Last Answer : Ans : c
Description : The ratio of work done per cycle to the stroke volume of the compressor is known as A. Compressor capacity B. Compression ratio C. Compressor efficiency D. Mean effective pressure
Description : In a single acting reciprocating compressor, the suction, compression and delivery of air takes place in A. One stroke B. Two stroke C. Three stroke D. Four stroke
Description : For low load operation more economical engine is a. petrol engine b. diesel engine c. muticylinder engine d. two stroke engine
Last Answer : ANSWER b. diesel engine
Description : Which of the following engine can work on very lean mixture a. Spark ignition engine b. compression ignition engine c. two stroke engine d. Four stroke engine
Last Answer : ANSWER b. compression ignition engine
Description : The term scavenging is generally associated with a. 2-stroke engine b. 4-stroke engine c. high efficiency engine d. diesel engine
Last Answer : ANSWER C. high efficiency engine
Description : An engine working on air standard Otto cycle has a cylinder diameter of 10 cm and stroke length of 15 cm. The ratio of specific heats for air is 1.4. If the clearance volume is 196.3 cc and the heat supplied per kg of air per ... kg of air is a. 879.1 kJ/ b. 890.2 kJ c. 895.3 kJ d. 973.5 kJ
Last Answer : ANSWER d. 973.5 kJ
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 : The piston of a steam engine moves in S.H.M. The crank rotates at 180 r.p.m. and the stroke length is 2 metres. The linear velocity of the piston when it is at a distance of 1 metre from the centre is a.8.88 m/sec b.16.32 m/sec c.5.88 m/sec d.8.16 m/sec e.Zero
Last Answer : e. Zero
Description : In the expansion stroke of a petrol engine, the piston is pushed with a great stroke. Why?
Last Answer : When the petrol-air mixture is ignited, carbon dioxide, carbon monoxide and water vapour expands suddenly. This exerts a great force on the piston.
Description : Give reason: Steam exerts great pressure on the walls of the piston during expansion stroke.
Last Answer : As steam occupies much larger volume than the same amount of water, it exerts great pressure on the walls of the piston.
Description : Piston displacement is the volume displaced by the piston during one stroke and is usually expressed in 1. Cubic meter 2.cubic inches 3. Both of these 4. none of these
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Description : hen displacement volume is divided by piston displacement, what will we obtained (a) number of cylinders (b) number of power stroke per minute for all cylinders (c) number of revolution of the crankshaft (engine) (d) number of revolution of crankshaft × number of cylinder
Last Answer : (b) number of power stroke per minute for all cylinders
Description : Air fuel ratio for idling speed of a petrol engine is approximately A. 1:1 B. 5:1 C. 20:1 D. 10:1
Description : Most high speed compression ignition engine operate on A. dual cycle B. otto cycle C. diesel cycle D.Carnot cycle
Description : In a battery ignition system, the intensity of spark is A. minimum at low engine speed B. minimum at low engine speed and increases with engine speed C. maximum al low engine speed and decreases with engine speed D. maximum at low engine speed
Description : Supercharging of an IC engine is done so that the A. thermal efficiency increases B. power output increases C. speed of the engine increases D. power output decreases
Description : The output of a diesel engine can be increased without increasing the engine speed or size in the following way A. feeding more fuel B. increasing the flywheel size C. heating intake air D. supercharging
Description : An engine indicator is used to determine the following A. Speed B. Temperature C. M.E.P D. Volume of cylinder
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 : The _____________ sensor, senses the movement of the throttle plate so that the mixture flow can be adjusted for engine speed and acceleration. a) throttle position b) manifold pressure c) camshaft position d) knock
Last Answer : Answer: a Explanation: The throttle position sensor, senses the movement of the throttle plate so that the mixture flow can be adjusted for engine speed and acceleration while the manifold ... the camshaft position sensor, senses rotation of engine camshaft for speed and timing of injection.
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
Description : In a variable speed SI engine, the maximum torque occurs at the maximum (a) Speed (b) Brake power (c) Indicated power (d) Volumetric efficiency
Description : In a centrifugal compressor, an increase in speed at a given pressure ratio causes A. Increase in flow B. Decrease in flow C. Increase in efficiency D. Increase in flow and decrease in efficiency
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
Description : Surging basically implies A. Unsteady, periodic and reversed flow B. Forward motion of air at a speed above sonic velocity C. The surging action due to the blast of air produced in a compressor D. Forward movement of aircraft
Description : The specific speed of a centrifugal compressor is generally A. less than that of reciprocating compressor B. independent of compressor type, but depends only on size of compressor C. higher ... axial compressor D. more than specific speed of reciprocating compressor but less than axial compressor
Description : In a centrifugal compressor an increase in speed at a given pressure ratio causes A. Increase in flow and increase in efficiency B. Increase in flow and decrease in efficiency C. Decrease in flow and increase in efficiency D. Decrease in flow and decrease in efficiency
Description : Which one of the following statements is correct? A. Reciprocating compressors are used to supply large quantities of air at a lower pressure ratio B. Centrifugal compressors are used to supply ... . Centrifugal compressors cannot be run at high speed because of impeller, diffuser and casing.
Description : Normally, an engine is warmed up at a. Full-speed with load. b. Full-speed without load. c. Reduced speed with load. d. Reduced speed without load.
Last Answer : ANSWER b. full-speed without load
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 : The knocking in spark ignition engines can be reduced by a. Retarding the spark. b. Increasing the engine speed. c. Both a and b d. None of these.
Last Answer : ANSWER c. Both a and b.
Description : A engine will generate maximum torque when it a. runs at maximum speed b. develops maximum power c. runs at lowest speed d. consumes more fuel
Last Answer : ANSWER c. runs at lowest speed