KNEC TVET: AUTOMOTIVE AND PLANT OPERATION | 100% VERIFIED
EXAM QUESTIONS & ANSWERS | LATEST 2026/2027 VERSION | PASS
GUARANTEE
1. What is the primary function of the crankshaft in an internal combustion
engine?
A. To open and close the engine valves
B. To convert reciprocating motion of pistons into rotational motion
C. To regulate the fuel injection timing
D. To circulate engine coolant
2. Which type of engine uses a glow plug instead of a spark plug?
A. Petrol engine
B. Wankel engine
C. Diesel engine
D. Gas turbine engine
3. The compression ratio of a diesel engine is typically:
A. 6:1 to 8:1
B. 8:1 to 10:1
C. 14:1 to 22:1
D. 25:1 to 30:1
4. What is the purpose of the camshaft in a four-stroke engine?
A. To balance the engine crankshaft
B. To drive the oil pump
C. To control the opening and closing of intake and exhaust valves
D. To regulate ignition timing only
5. Which stroke in a four-stroke engine involves both intake and exhaust
valves being closed?
A. Intake stroke
B. Exhaust stroke
C. Compression stroke
D. Power stroke
,6. The function of piston rings in an engine is to:
A. Reduce piston weight and balance rotation
B. Seal the combustion chamber and control oil consumption
C. Connect the piston to the connecting rod
D. Lubricate the cylinder walls only
7. What is volumetric efficiency in an engine?
A. The ratio of fuel burned to fuel supplied
B. The ratio of actual air-fuel mixture drawn in to the theoretical
maximum
C. The mechanical efficiency of the piston rings
D. The ratio of brake power to indicated power
8. An overhead valve (OHV) engine has its camshaft located:
A. In the cylinder head
B. Above the rocker arms
C. In the engine block beside the crankshaft
D. Directly on the valve stems
9. Which component prevents the engine from running backwards after
starting?
A. Flywheel ring gear
B. One-way roller clutch in the starter motor
C. Crankshaft position sensor
D. Timing belt tensioner
10. The firing order 1-3-4-2 is most common in a:
A. V8 engine
B. Six-cylinder in-line engine
C. Four-cylinder in-line engine
D. Flat-four engine
11. Which fuel system component is responsible for maintaining fuel
pressure in a fuel-injected engine?
A. Fuel filter
B. Fuel pressure regulator
C. Throttle body
D. Idle air control valve
12. The stoichiometric air-fuel ratio for a petrol engine is:
A. 10:1
B. 12.5:1
C. 14.7:1
, D. 16:1
13. A carburetor float circuit is designed to:
A. Provide extra fuel during acceleration
B. Maintain a constant fuel level in the float bowl
C. Enrich the mixture during cold starting
D. Control idle mixture
14. Common Rail Direct Injection (CRDi) systems operate at fuel pressures
of:
A. 100-200 bar
B. 1000-2000 bar
C. 5-10 bar
D. 50-100 bar
15. What is the purpose of the diesel injector return line?
A. To supply high-pressure diesel to the injector
B. To return excess fuel from injectors back to the tank
C. To purge air from the fuel system
D. To recirculate diesel for cooling
16. Which type of fuel injection delivers fuel directly into the combustion
chamber?
A. Throttle body injection (TBI)
B. Multi-point port injection (MPFI)
C. Direct injection (GDI/FSI)
D. Central port injection (CPI)
17. The function of the fuel pressure relief valve is to:
A. Open when pressure exceeds safe limits, protecting the system
B. Regulate flow to the carburettor
C. Prime the fuel system after filter replacement
D. Control the idle speed
18. What does a lambda sensor (O2 sensor) monitor in a fuel system?
A. Fuel temperature
B. Fuel pressure upstream of the injectors
C. Oxygen content in the exhaust gas to enable closed-loop fuelling
D. Air mass flow into the intake manifold
19. Diesel fuel cetane number is a measure of:
A. Energy content per litre
B. Ignition quality and ease of self-ignition
, C. Viscosity at low temperatures
D. Sulphur content
20. In a diesel injection pump, what component sets maximum fuel delivery?
A. Governor
B. Delivery valve
C. Timing advance unit
D. Transfer pump
21. The primary winding of an ignition coil is connected to:
A. The spark plugs directly
B. The battery through the ignition switch and breaker
points/transistor
C. The distributor cap terminals
D. The engine management unit output stage only
22. Ignition timing advance with increasing engine speed is achieved by the:
A. Vacuum advance unit
B. Centrifugal advance mechanism
C. Electronic control unit
D. Both B and C are correct
23. What is the function of the ignition distributor cap?
A. To store high-voltage energy temporarily
B. To route high-voltage pulses from the coil to the correct spark
plug
C. To trigger the ignition coil at the correct time
D. To reduce electromagnetic interference
24. Spark plug heat range refers to:
A. The maximum temperature the electrode can withstand before melting
B. The ability of the plug to transfer heat from the ceramic insulator
to the engine
C. The temperature of the spark produced
D. The voltage required to fire the plug
25. In a distributorless ignition system (DIS), ignition timing is controlled by:
A. Mechanical breaker points
B. The vacuum advance unit
C. The engine control module (ECM)
D. The centrifugal advance weights
26. What is the primary function of engine oil?
EXAM QUESTIONS & ANSWERS | LATEST 2026/2027 VERSION | PASS
GUARANTEE
1. What is the primary function of the crankshaft in an internal combustion
engine?
A. To open and close the engine valves
B. To convert reciprocating motion of pistons into rotational motion
C. To regulate the fuel injection timing
D. To circulate engine coolant
2. Which type of engine uses a glow plug instead of a spark plug?
A. Petrol engine
B. Wankel engine
C. Diesel engine
D. Gas turbine engine
3. The compression ratio of a diesel engine is typically:
A. 6:1 to 8:1
B. 8:1 to 10:1
C. 14:1 to 22:1
D. 25:1 to 30:1
4. What is the purpose of the camshaft in a four-stroke engine?
A. To balance the engine crankshaft
B. To drive the oil pump
C. To control the opening and closing of intake and exhaust valves
D. To regulate ignition timing only
5. Which stroke in a four-stroke engine involves both intake and exhaust
valves being closed?
A. Intake stroke
B. Exhaust stroke
C. Compression stroke
D. Power stroke
,6. The function of piston rings in an engine is to:
A. Reduce piston weight and balance rotation
B. Seal the combustion chamber and control oil consumption
C. Connect the piston to the connecting rod
D. Lubricate the cylinder walls only
7. What is volumetric efficiency in an engine?
A. The ratio of fuel burned to fuel supplied
B. The ratio of actual air-fuel mixture drawn in to the theoretical
maximum
C. The mechanical efficiency of the piston rings
D. The ratio of brake power to indicated power
8. An overhead valve (OHV) engine has its camshaft located:
A. In the cylinder head
B. Above the rocker arms
C. In the engine block beside the crankshaft
D. Directly on the valve stems
9. Which component prevents the engine from running backwards after
starting?
A. Flywheel ring gear
B. One-way roller clutch in the starter motor
C. Crankshaft position sensor
D. Timing belt tensioner
10. The firing order 1-3-4-2 is most common in a:
A. V8 engine
B. Six-cylinder in-line engine
C. Four-cylinder in-line engine
D. Flat-four engine
11. Which fuel system component is responsible for maintaining fuel
pressure in a fuel-injected engine?
A. Fuel filter
B. Fuel pressure regulator
C. Throttle body
D. Idle air control valve
12. The stoichiometric air-fuel ratio for a petrol engine is:
A. 10:1
B. 12.5:1
C. 14.7:1
, D. 16:1
13. A carburetor float circuit is designed to:
A. Provide extra fuel during acceleration
B. Maintain a constant fuel level in the float bowl
C. Enrich the mixture during cold starting
D. Control idle mixture
14. Common Rail Direct Injection (CRDi) systems operate at fuel pressures
of:
A. 100-200 bar
B. 1000-2000 bar
C. 5-10 bar
D. 50-100 bar
15. What is the purpose of the diesel injector return line?
A. To supply high-pressure diesel to the injector
B. To return excess fuel from injectors back to the tank
C. To purge air from the fuel system
D. To recirculate diesel for cooling
16. Which type of fuel injection delivers fuel directly into the combustion
chamber?
A. Throttle body injection (TBI)
B. Multi-point port injection (MPFI)
C. Direct injection (GDI/FSI)
D. Central port injection (CPI)
17. The function of the fuel pressure relief valve is to:
A. Open when pressure exceeds safe limits, protecting the system
B. Regulate flow to the carburettor
C. Prime the fuel system after filter replacement
D. Control the idle speed
18. What does a lambda sensor (O2 sensor) monitor in a fuel system?
A. Fuel temperature
B. Fuel pressure upstream of the injectors
C. Oxygen content in the exhaust gas to enable closed-loop fuelling
D. Air mass flow into the intake manifold
19. Diesel fuel cetane number is a measure of:
A. Energy content per litre
B. Ignition quality and ease of self-ignition
, C. Viscosity at low temperatures
D. Sulphur content
20. In a diesel injection pump, what component sets maximum fuel delivery?
A. Governor
B. Delivery valve
C. Timing advance unit
D. Transfer pump
21. The primary winding of an ignition coil is connected to:
A. The spark plugs directly
B. The battery through the ignition switch and breaker
points/transistor
C. The distributor cap terminals
D. The engine management unit output stage only
22. Ignition timing advance with increasing engine speed is achieved by the:
A. Vacuum advance unit
B. Centrifugal advance mechanism
C. Electronic control unit
D. Both B and C are correct
23. What is the function of the ignition distributor cap?
A. To store high-voltage energy temporarily
B. To route high-voltage pulses from the coil to the correct spark
plug
C. To trigger the ignition coil at the correct time
D. To reduce electromagnetic interference
24. Spark plug heat range refers to:
A. The maximum temperature the electrode can withstand before melting
B. The ability of the plug to transfer heat from the ceramic insulator
to the engine
C. The temperature of the spark produced
D. The voltage required to fire the plug
25. In a distributorless ignition system (DIS), ignition timing is controlled by:
A. Mechanical breaker points
B. The vacuum advance unit
C. The engine control module (ECM)
D. The centrifugal advance weights
26. What is the primary function of engine oil?
