Description : The method of determination of indicated power of multi cylinder SI engine is by use of (a) Morse test (b) Prony brake test (c) Motoring test (d) Heat balance test
Last Answer : Ans : a
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
Last Answer : ANSWER : B
Description : The relation between Indicated power (ip), Friction power (fp) and Brake power (bp) is a. ip = fp – bp b. ip = fp + bp c. bp = ip + fp d. bp = ip / fp (Ans:b)
Last Answer : Which of the following is not true for internal combustion engine as compare to external combustion engine? a. It has lower ratio of weight to output b. They are self starting c. Higher overall efficiency d. Mechanical simplicity (Ans:b)
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 : 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 : An engine produces 10 kW brake power while working with a brake thermal efficiency of 30%. If the calorific value of the fuel used is 40000 kJ/kg, then what is the fuel consumption? (a) 1.5 kg/hour (b) 3 kg/hour (c) 0.3 kg/hour (d) 1 kg/hour
Last Answer : Ans :b
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 : 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 : Which one of the following types of compressor is mostly used for supercharging of IC engines? (a) Radial flow compressor (b) Axial flow compressor (c) Root blower (d) Reciprocating compressor
Last Answer : Ans : c
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 : Ratio of actual indicated work to hypothetical indicated work in a steam engine is the (a) Indicated thermal efficiency (b) Friction factor (c) Mechanical efficiency (d) Diagram factor
Last Answer : Ans : d
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 : Disadvantage of hydrogen as a fuel in IC engine is a) storage is safe b) low NOx c) detonating tendency d) easy handling
Last Answer : Answer: c 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.
Description : All heat engines utilize a. lower heating value of oil b. higher heating value of oil c. net calorific value of oil d. calorific value of fuel
Last Answer : ANSWER a. lower heating value of oil
Description : The air fuel ratio in petrol engines is controlled by a. valve opening / closing b. governing c. carburetion d. scavenging
Last Answer : ANSWER c. carburetion
Description : Scavenging is usually done to increase the a. thermal efficiency b. speed c. power output d. fuel consumption
Last Answer : ANSWER c. power output
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 : 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 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 : Specific fuel consumption is defined as a. fuel consumption per hour b. fuel consumed per km. c. fuel consumed per BHP d. fuel consumed per hour per BHP
Last Answer : ANSWER d. fuel consumed per hour per BHP
Description : The specific fuel consumption per BHP hour for petrol engine is approximately a. 0.1 kg b. 0.2 kg c. 0.25 kg d. 0.35 kg
Last Answer : ANSWER c. 0.25 kg
Description : The specific fuel consumption per BHP hour for diesel engine is approximately a. 0.1 kg b. 0.2 kg c. 0.3 kg d. 0.4 kg
Last Answer : ANSWER b. 0.2 kg
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 : 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
Description : The ratio of indicated power to shaft power of the engine required to drive the compressor is called A. Compressor efficiency B. Volumetric efficiency C. Isothermal efficiency D. Mechanical efficiency
Description : Compressor mostly used for supercharging of IC engine is A. Radial flow compressor B. Axial flow compressor C. Root blower compressor D. Reciprocating compressor
Last Answer : ANSWER : A
Description : State the drawbacks of carbureted (SI) engines on the basis of fuel distribution, emission, power output and fuel consumption.
Last Answer : Drawbacks of carburetted S.I. engine: 1) Fuel distribution- Mal-distribution of charge. 2) Emission- More emissin 3) Power output- Less 4) Fuel consumption - More
Description : Supercharging is essential in A. aircraft engines B. petrol engines C. gas turbines D. diesel engines
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 : 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
Description : 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
Last Answer : Answer: b Explanation: Generally, with EFI of diesel engines very high injection pressure can be obtained.
Description : Anti-knock for compression ignition engines is a) napthene b) tetra ethyl lead c) amyl nitrate d) hexadecane
Last Answer : Answer: c Explanation: Amyl nitrate is the anti-knock for compression ignition engines.
Description : The knocking tendency in CI engines increases with (a) Increase of coolant water temperature (b) Increase of temperature of inlet air (c) Decrease of compression ratio (d) Increase of compression ratio
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 SI engines knocking can be reduced by (a) Increasing the compression ratio (b) Increasing the cooling water temperature (c) Retarding the spark advance (d) Increasing the inlet air temperature
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 : 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 : 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 : 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 : Octane number of petrol normally used in petrol engines is of the order of a. 20-30 b. 40-60 c. 60-70 d. 80-90
Last Answer : ANSWER d. 80-90
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
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 : 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 : 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 : 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 : The formation of frost on cooling coils in a refrigerator (a) increases heat transfer (b) improves C.O.P. of the system (c) increases power consumption (d) reduces power consumption
Last Answer : Ans: c
Description : Moisture in freon refrigeration system causes (a) ineffective refrigeration (b) high power consumption (c) freezing automatic regulating valve (d) corrosion of whole system