Module 16 Piston Engine Final Practice Exam (72 Questions 90 Mints)

Module -16 (Piston Engine)

Final Practice Exam Test

  

 

1. How does a piston engine convert heat energy into mechanical energy?
   1.   By compressing fuel vapor for ignition
   2.   By burning fuel to create pressure that moves the pistons
   3.   By heating oil to lubricate moving parts
2. If an engine is running rough at idle but smooths out at higher RPM, what could be the cause??
   1.   A worn-out crankshaft
   2.   Fouled spark plugs
   3.   A clogged fuel filter
3. The purpose of a crankshaft counterweight is to?
   1.   Balance the crankshaft and reduce vibration
   2.   Increase power output
   3.   Lubricate the crankshaft
4. Which factor determines the octane rating of aviation fuel?
   1.   Its boiling point
   2.   Its resistance to detonation
   3.   Its weight
5. The function of a fuel strainer is to?
   1.   Enrich the fuel mixture
   2.   Increase fuel pressure
   3.   Remove water and debris from the fuel
6. What can cause engine knocking (detonation)?
   1.   Running a rich mixture
   2.   Increasing oil viscosity
   3.   Using a lower-than-required octane fuel
7. What is the purpose of the oil sump?
   1.   To mix oil with fuel
   2.   To store and supply oil to the engine
   3.   To cool engine cylinders
8. The camshaft is driven byThe camshaft is driven by?
   1.   The starter motor
   2.   The magneto
   3.   The crankshaft
9. What is the purpose of the float chamber in a carburetor?
   1.   To maintain a constant fuel level for proper mixture
   2.   To cool the fuel
   3.   To regulate air intake
10. The stroke of an engine refers to?
    1.   The rotation of the crankshaft
    2.   The duration of the combustion process
    3.   The distance a piston travels from top dead center (TDC) to bottom dead center (BDC)
11. Which component transfers motion from the camshaft to the valves?
    1.   Pushrods and rocker arms
    2.   Connecting rod
    3.   Crankshaft
12. The function of an oil cooler is to ?
    
    1.   Increase fuel pressure
    2.   Reduce fuel temperature
    3.   Maintain optimum oil temperature
13. What is the primary function of a piston in an internal combustion engine?
    
    1.   To regulate the intake and exhaust valves
    2.   To convert heat energy into mechanical motion
    3.   To control the fuel-air mixture
14. The four strokes of a piston engine occur in the following order ?
    1.   Intake, Power, Exhaust, Compression
    2.   Intake, Compression, Power, Exhaust
    3.   Compression, Intake, Exhaust, Power
15. In a four-stroke engine, during which stroke does the intake valve open?
    1.   Intake
    2.   Compression
    3.   Power
16. What is the function of the camshaft in a piston engine?
    1.   To maintain fuel pressure
    2.   To increase power output
    3.   To control the opening and closing of the valves
17. TThe clearance volume in a cylinder is the volume?
    1.   Above the piston at bottom dead center
    2.   Between the cylinder head and piston at top dead center
    3.   Displaced by the piston during one revolution
18. The compression ratio of an aircraft piston engine typically ranges between?
    
    1.   6:1 and 9:1
    2.   2:1 and 4:1
    3.   12:1 and 15:1
19. Which type of lubrication system is commonly used in aircraft piston engines?
    
    1.   Two-stroke oil injection
    2.   Gravity-fed lubrication
    3.   Wet sump and dry sump
20. The function of a crankshaft is to?
    
    1.   Maintain the correct air-fuel ratio
    2.   Open and close the engine valves
    3.   Convert reciprocating motion into rotary motion
21. What is the purpose of a magneto in a piston engine?
    
    1.   To regulate fuel flow
    2.   To generate electrical power for the aircraft
    3.   To provide high-voltage current for spark plugs
22. A rich air-fuel mixture means?
    
    1.   Equal amounts of air and fuel
    2.   Excess air compared to fuel
    3.   Excess fuel compared to air
23. What is detonation in a piston engine?
    1.   The sudden and uncontrolled explosion of fuel in the cylinder
    2.   The premature burning of fuel before the spark plug fires
    3.   The normal combustion process
24. How is an engine’s power output increased?
    1.   Increasing fuel density
    2.   Increasing engine RPM and fuel-air mixture
    3.   Decreasing compression ratio
25. The function of a carburetor is to?
    1.   Mix fuel and air in the correct ratio
    2.   Control engine timing
    3.   Regulate oil flow
26. A turbocharger increases engine power by ?
    1.   Reducing engine temperature
    2.   Compressing intake air before it enters the cylinders
    3.   Increasing fuel flow
27. If the fuel-air mixture is too lean, what is a possible consequence?
    1.   Increased engine power
    2.   Reduced fuel consumption
    3.   Engine overheating and possible detonation
28. What is the function of the spark plug in a piston engine?
    1.   To generate electricity
    2.   To ignite the air-fuel mixture
    3.   To control valve timing
29. The function of piston rings includes?
    1.   Increasing engine RPM
    2.   Regulating oil pressure
    3.   Sealing the combustion chamber
30. In a horizontally opposed piston engine, the cylinders are arranged ?
    1.   In a V-shape
    2.   On opposite sides of the crankshaft
    3.   In a single row
31. Which material is commonly used for aircraft piston engine cylinders?
    1.   Steel alloy
    2.   Nickel alloy
    3.   Aluminum alloy
32. The valve timing in a four-stroke engine is controlled by ?
    1.   The ignition system
    2.   The crankshaft
    3.   The camshaft
33. The power output of an engine is measured in?
    1.   Torque
    2.   Horsepower
    3.   Pounds per square inch
34. What is the function of an oil control ring in a piston?
    1.   To prevent excessive oil consumption
    2.   To maintain high compression
    3.   To increase fuel efficiency
35. The purpose of valve springs in an engine is to?
    1.   Keep valves closed when necessary
    2.   Increase engine power
    3.   Maintain pressure in the cylinder
36. If an engine experiences pre-ignition, what is likely the cause?
    1.   High oil temperature
    2.   Low fuel pressure
    3.   Excessive carbon deposits
37. A dry sump lubrication system is used to ?
    1.   Increase oil pressure
    2.   Store oil in a separate tank
    3.   Prevent engine overheating
38. What is the function of a crankcase breather?
    1.   To regulate fuel flow
    2.   To remove excess air-fuel mixture
    3.   To release pressure and prevent oil leaks
39. Which component controls the ignition timing in a piston engine?
    1.   Carburetor
    2.   Magneto
    3.   Oil pump
40. The term "stoichiometric ratio" refers to?
    1.   The highest power-producing fuel mixture
    2.   The ideal fuel-to-air mixture for complete combustion
    3.   The lowest fuel consumption ratio
41. What is the primary function of an engine governor?
    1.   To regulate fuel flow
    2.   To control RPM automatically
    3.   To prevent overheating
42. Which fuel type is commonly used in aircraft piston engines?
    1.   Diesel
    2.   AVGAS
    3.   Kerosene
43. An excessive lean mixture can cause?
    1.   Increased fuel consumption
    2.   Increased power output
    3.   Engine overheating and knocking
44. The main advantage of using an opposed-type engine in aircraft is?
    1.   It provides a more compact and balanced design
    2.   It increases engine weight
    3.   It is easier to manufacture
45. The function of a tappet (lifter) in an engine is to?
    1.   Regulate oil pressure
    2.   Control air-fuel mixture
    3.   Transfer camshaft motion to the valves
46. Which of the following is a symptom of valve clearance being too tight?
    1.   Poor compression and valve damage
    2.   High oil pressure
    3.   Increased fuel efficiency
47. What is a main purpose of a choke in a carburetor?
    1.   To increase air intake
    2.   To reduce fuel consumption
    3.   To enrich the fuel mixture for cold starts
48. What does the term "dead center" refer to in a piston engine?
    1.   The moment fuel ignites
    2.   The position where the piston is at its highest or lowest point
    3.   The maximum fuel pressure point
49. What is one disadvantage of a radial engine?
    1.   Reduced engine efficiency
    2.   Increased vibration
    3.   Difficult cooling
50. A weak valve spring can cause?
    1.   Loss of compression and engine misfire
    2.   Increased fuel efficiency
    3.   Higher oil pressure
51. The main function of an engine baffling system is to?
    1.   Improve engine lubrication
    2.   Increase exhaust pressure
    3.   Direct cooling airflow over the cylinders
52. A lean mixture is generally used during ?
    1.   Cruise flight
    2.   Takeoff
    3.   Engine start
53. The ignition timing in a piston engine is based on?
    1.   Fuel pressure
    2.   Manifold pressure
    3.   Crankshaft position
54. The purpose of a piston pin is to?
    1.   Secure the piston to the connecting rod
    2.   Maintain valve timing
    3.   Control oil pressure
55. An excessive valve clearance will cause?
    1.   Increased valve noise and poor performance
    2.   Engine overheating
    3.   Higher oil pressure
56. The international marking for a fire protection pipe line is a series of ?
    1.   circles
    2.   squares
    3.   diamonds
57. The term "bottom dead center" (BDC) refers to?
    1.   The highest point in the compression stroke
    2.   The moment the fuel ignites
    3.   The lowest position of the piston in the cylinder
58. What is the purpose of valve overlap in a four-stroke engine?
    1.   To reduce fuel consumption
    2.   To improve volumetric efficiency
    3.   To control exhaust emissions
59. If a piston ring breaks, what is a likely symptom?
    1.   Increased oil consumption and loss of compression
    2.   Higher fuel pressure
    3.   Reduced spark plug wear
60. If an engine is running at a high altitude, the fuel-air mixture should be?
    1.   Enriched
    2.   Leaned
    3.   Kept constant
61. The function of the throttle valve in a carburetor is to?
    1.   Regulate airflow and engine power
    2.   Increase fuel flow
    3.   Control engine temperature
62. What does a manifold absolute pressure (MAP) gauge measure?
    1.   The fuel pressure
    2.   The oil pressure
    3.   The pressure in the intake manifold
63. Which component maintains engine timing and synchronization?
    1.   The ignition switch
    2.   The crankshaft and camshaft
    3.   The magneto
64. The expansion ratio of an engine is the ratio between ?
    1.   The volume before and after combustion
    2.   The oil pressure before and after circulation
    3.   The air pressure inside the intake manifold
65. In a direct-drive engine, the propeller is connected to ?
    1.   The crankshaft
    2.   The camshaft
    3.   The accessory gearbox
66. The best mixture setting for takeoff is ?
    1.   Full lean
    2.   Full rich
    3.   70% power
67. If a piston engine’s oil pressure is too low, it may indicate ?
    1.   Higher power output
    2.   Better fuel economy
    3.   Oil pump failure or excessive wear
68. What is the primary purpose of an impulse coupling in a magneto?
    1.   To advance the spark timing
    2.   To prevent detonation
    3.   To retard ignition timing for starting
69. If an aircraft piston engine experiences detonation, what corrective action should be taken?
    1.   Reduce oil pressure
    2.   Increase throttle and lean the mixture
    3.   Reduce manifold pressure and enrich the mixture
70. What is the effect of a clogged fuel injector in a fuel-injected engine?
    1.   Increase in fuel flow
    2.   Rough engine operation and power loss
    3.   Higher oil temperature
71. A high oil consumption rate in an engine is most likely due to ?
    1.   A lean fuel setting
    2.   Excess fuel in the mixture
    3.   Worn piston rings or valve guides
72. If the ignition timing is too advanced, what symptom may occur?
    1.   Engine knocking (detonation)
    2.   Lower cylinder head temperature
    3.   Increased manifold pressure

Read More