Description : Engine pistons are usually made of aluminium alloy as it a. is lighter b. wears less c. absorbs shocks d. is stronger
Last Answer : ANSWER a. is lighter
Description : A diesel engine is usually more efficient than a spark ignition engine because a. Diesel being a heavier hydrocarbon, release more heat per kg than gasoline b. The air standard efficiency of diesel ... an Spark ignition engine d.Self ignition temperature of diesel is higher than that of gasoline.
Last Answer : ANSWER c. The compression ratio of a diesel engine is higher than that of an S.I engine
Description : Reducing suction pressure in refrigeration cycle (a) lowers evaporation temperature (b) increases power required per ton of refrigeration (c) lowers compressor capacity because vapour is lighter (d) all of the above.
Last Answer : Ans: d
Description : When air passes through silica gel, A. it absorbs water vapour molecules B. latent heat of condensation is released C.dbt of air increases D. all of the mentioned
Last Answer : ANSWER : D
Description : The back pressure of petrol engine is usually a. 1 ata b. 1.2 ata c. 0.8 ata d. 2 ata.
Last Answer : ANSWER b. 1.2 ata
Description : For ammonia refrigerating systems, the tubes of a shell and tube condenser are made of (a) copper (b) aluminium (c) steel (d) brass
Last Answer : Ans: c
Description : An egg sinks in soft water but floats in a concentrated solution of salt because – (1) Egg absorbs salt from the solution and expands (2) Albumin dissolves in salt solution and egg becomes lighter (3) The density of salt solution exceeds the density of eggs (4) Water has high surface tension
Last Answer : (3) The density of salt solution exceeds the density of eggs Explanation: Following the density principle, the density of the egg compared to the density of the tap water is lesser (the density principle ... and that is why an egg sinks in soft water but floats in a concentrated solution of salt.
Description : An egg sinks in soft water but floats in a concentrated solution of salt because (1) egg absorbs salt from the solution and expands (2) albumin dissolves in salt solution and egg becomes lighter (3) the density of salt solution exceeds the density of eggs (4) water has high surface tension
Last Answer : the density of salt solution exceeds the density of eggs
Description : Air fuel ratio at which a petrol engine cannot work is A. 8:1 B. 12:1 C. 15:1 D. 20:1 and less
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 size of inlet valve of an engine in comparison to exhaust valve is A. more B. less C. same D. varies from design to design
Last Answer : ANSWER : B
Description : A diesel engine compared to petrol engine, running at full load is A. less efficient B. equally efficient C. more efficient D. other factors will decide it
Description : The specific fuel consumption of a petrol engine compared to diesel engine of same H.P is A. same B.more C. less D. unpredictable
Description : The air requirement of a petrol engine during starting compared to the theoretical air requirement for complete combustion is A. more B.unpredictable C. same D. less
Description : The air requirement of a petrol engine during starting compared to theoretical air required for complete combustion is a. more b. less c. same d. may be more or less depending on engine capacity
Last Answer : ANSWER b. less
Description : Air fuel ratio at which a petrol engine cannot work is a. 8:1 b. 10:1 c. 20:1 and less d. 15:1
Last Answer : ANSWER c. 20:1 and less
Description : In diesel engine, the compression ratio as compared with the expansion ratio is a. same b. less c. more d. variable
Last Answer : ANSWER c. more
Description : The value of COP in vapour compression cycle is usually (a) always less than unity (b) always more than unity (c) equal to unity (d) any one of the above
Last Answer : Ans: b
Description : In which step of the four-stroke engine cycle does the heat from the combustion reaction causes the pistons to move?
Last Answer : combustion and expansion
Description : Why pistons are usually dished at top ?
Last Answer : Pistons are usually hollowed at top to (i) provide greater spa’e for combustion, (ii) increase surface for flue gases to act upon, and (iii) better distribution of stresses.
Description : Polypropylene compared to polythene is (A) Harder (B) Stronger (C) Lighter (D) All (A), (B) and (C)
Last Answer : (D) All (A), (B) and (C)
Description : Efficiency of a Carnot engine is given as 80%. If the- cycle direction be reversed, what will be the value of COP ofreversed Carnot cycle (a) 1.25 (b) 0.8 (c) 0.5 (d) 0.25
Description : In two stroke engine one power occurs in _______ of crank rotation A. 180° B. 360° C. 270° D. 720°
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 knock in diesel engine occurs due to A. instantaneous and rapid burning of the first part of the charge B. instantaneous auto ignition of the last part of the charge C. delayed burning of the last part of the charge D. reduction of delay period
Last Answer : ANSWER : A
Description : A 5 BHP engine running at full load would consume diesel of the order of A. 0.3 kg/hr B. 1 kg/hr C. 3 kg/hr D. 5 kg/hr
Last Answer : ANSWER ; B
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 : The theoretically correct air fuel ratio of a petrol engine is of the order of A. 6:1 B. 10:1 C. 15:1 D. 20:1
Description : The reason for supercharging in any engine is to be A. increase efficiency B. increase power C. effect fuel economy D. reduce weight and bulk for a given output
Description : The fuel air ratio in a petrol engine fitted with suction carburetor, operating with dirty air filter as compared to clean filter will be A. higher B. lower C. remain unaffected D. unpredictable
Description : Most high speed compression ignition engine operate on A. dual cycle B. otto cycle C. diesel cycle D.Carnot cycle
Description : Octane number of gasoline is obtained by comparing the performance of the engine when running on a mixture of the following hydrocarbons A. ethane and methane B. normal heptane and iso-octane C. iso-heptane and octane D. iso-octane and TEL
Description : HUCR is the highest compression ratio at which the A. engine can be run B. engine gives maximum output C. engine is most efficient D. fuel can be used in a test engine without detonation
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
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 : Ignition timing of a multi-cylinder SI engine can be adjusted by A. rotating the cam shaft B. adjusting the generator pulley C. rotating the distributor D. adjusting the pump pulley
Description : By supercharging the power output of an engine is expected to increase by A. 20% B. 45% C. 75% D. 50%
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 : 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 : A 100 cc engine has thefollowingparameter as 100 cc A. fuel tankcapacity B. sweptvolume C. luboilcapacity D. clearence volumen
Description : In diesel engine the fuel injected would burn instantaneously at about compressed air temperature of A. 1000°C B. 250°C C. 450°C D. 2000°C
Description : The air-fuel ratio of the petrol engine is governed by A. fuel pump B. governor C. carburetor D. injector
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
Description : As a result of detonation in an I.C engine, following parameter attains a high value A. peak temperature B. peak pressure C. rate of pressure rise D. rate of temperature rise
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 : 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
Description : The specific fuel consumption for diesel engine is approximately A. 0.15 kg/kWh B. 0.2 kg/kWh C. 28 kg/kWh D. 0.36 kg/kWh
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°
Description : An engine indicator is used to determine the following A. Speed B. Temperature C. M.E.P D. Volume of cylinder
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