IC Engines MCQ - Page 2
IC Engines MCQ includes key topics like SI and CI engines, combustion, fuel systems, thermodynamic cycles, performance parameters, and emissions. These objective questions help students strengthen engine fundamentals for mechanical engineering and competitive exams.
Q21. Which of the following is a two-stroke engine part?
A. Valves
B. Ports
C. Camshaft
D. Pushrod
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Q22. Power stroke occurs when?
A. Piston moves down
B. Piston moves up
C. Piston stops
D. Engine stops
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Q23. Volumetric efficiency is?
A. Actual/Ideal volume of air
B. Heat/Work
C. Fuel/Air ratio
D. Pressure/Volume
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Q24. Air–fuel ratio in diesel engine is?
A. Constant
B. Variable
C. Equal to petrol
D. Not required
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Q25. Crankcase ventilation removes?
A. Oil
B. Fuel
C. Blow-by gases
D. Coolant
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Q26. Cooling system in IC engine prevents?
A. Fuel injection
B. Overheating
C. Lubrication
D. Ignition
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Q27. The ideal efficiency of Diesel cycle depends on?
A. Cut-off ratio
B. Compression ratio
C. Both A and B
D. Temperature
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Q28. The fuel injector is used in?
A. Petrol engine
B. Steam engine
C. Diesel engine
D. Gas turbine
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Q30. Catalytic converter reduces?
A. HC, CO, NOx
B. Only CO2
C. Only soot
D. Only oxygen
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Q31. Main function of piston rings is?
A. Store oil
B. Prevent gas leakage
C. Generate spark
D. Control speed
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Q32. Flash point of fuel is?
A. Auto-ignition temp
B. Lowest temperature at which vapour ignites
C. Burning temperature
D. Cooling temperature
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Q33. Specific fuel consumption (SFC) is?
A. Fuel/Power
B. Air/Fuel
C. Power/Time
D. Fuel/Volume
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Q34. The calorific value of diesel is approx?
A. 2000 kcal/kg
B. 5000 kcal/kg
C. 11000 kcal/kg
D. 20000 kcal/kg
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Q35. Which turbocharger uses exhaust gases?
A. Electric turbo
B. Mechanical blower
C. Exhaust turbocharger
D. Cooling fan
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Q36. Spark timing in petrol engine is controlled by?
A. Injector
B. Crankshaft
C. Ignition system
D. Fuel tank
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Q37. Diesel engines operate on?
A. Constant pressure heat addition
B. Constant volume heat addition
C. Both
D. Neither
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Q38. Stoichiometric mixture means?
A. Rich mixture
B. Lean mixture
C. Chemically correct mixture
D. Dry mixture
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Q39. Which engine has higher thermal efficiency?
A. Petrol engine
B. Diesel engine
C. Gas engine
D. Steam engine
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Q40. Throttle valve is used in?
A. Diesel engine
B. Petrol engine
C. Steam engine
D. Gas turbine
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